Siga este enlace para ver otros tipos de publicaciones sobre el tema: Whole engine modelling.
Artículos de revistas sobre el tema "Whole engine modelling"
Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros
Consulte los 50 mejores artículos de revistas para su investigación sobre el tema "Whole engine modelling".
Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.
También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.
Explore artículos de revistas sobre una amplia variedad de disciplinas y organice su bibliografía correctamente.
1
Chen, G. "Vibration modelling and verifications for whole aero-engine". Journal of Sound and Vibration 349 (agosto de 2015): 163–76. http://dx.doi.org/10.1016/j.jsv.2015.03.029.
Texto completo
2
Lolis, P., P. Giannakakis, V. Sethi, A. J. B. Jackson y P. Pilidis. "Evaluation of aero gas turbine preliminary weight estimation methods". Aeronautical Journal 118, n.º 1204 (junio de 2014): 625–41. http://dx.doi.org/10.1017/s0001924000009404.
Texto completoResumen
AbstractThe estimation of gas turbine engine weight during the preliminary or conceptual design phase is a key part of a Techno-economic Environmental Risk Analysis (TERA). Several methods that are available in the public domain are analysed and compared, in order to establish the physics driving them and their suitability for the weight estimation of modern gas turbine engines. Among the tested methods, only WATE managed to achieve acceptable accuracy for engine optimisation studies. This work demonstrates that the age and restrictions of existing ‘whole engine based’ methods, along with their dependency on old engine databases make them unsuitable for future and novel aero engines. A hybrid weight modelling approach is proposed as a solution permitting the creation of simple ‘whole engine based’ methods that do not depend on the availability of existing engine data, which are also subject to uncertainties and incoherencies.
3
Giuntini, Sabrina, Antonio Andreini, Bruno Facchini, Marco Mantero, Marco Pirotta y Sven Olmes. "Transient 2D FEM-fluid network coupling for thermo-mechanical whole gas turbine engine simulations: modelling features and applications". E3S Web of Conferences 197 (2020): 10012. http://dx.doi.org/10.1051/e3sconf/202019710012.
Texto completoResumen
In order to control the thermo-mechanical stresses that large heavy-duty power generation turbines have to face nowadays in their frequent operational transients, the analysis of the heat transfer between main flow, secondary air systems and structural components has to consider multi-physics coupled interactions, and has to be carried out with a whole engine modelling approach, simulating the entire machine in the real operating conditions. This is fundamental to guarantee a reliable assessment of life timing consumption and optimize clearances and temperature picks, through an efficient secondary air system design. It is here proposed a comprehensive description of modelling features and assumptions needed for the transient thermo-mechanical characterization of the whole engine through the application of a FEM-fluid network coupling methodology developed in collaboration with Ansaldo Energia and based on the open source code CalculiX®. In the present work the transient thermal modelling capability of the procedure will be verified through its application to a real whole engine geometry under a realistic transient cycle, comparing results with those of a reference FEM code.
4
Giuntini, Sabrina, Antonio Andreini, Giulio Cappuccini y Bruno Facchini. "Finite element transient modelling for whole engine-secondary air system thermomechanical analysis". Energy Procedia 126 (septiembre de 2017): 746–53. http://dx.doi.org/10.1016/j.egypro.2017.08.231.
Texto completo
5
Giannella, Venanzio, Raffaele Sepe, Roberto Citarella y Enrico Armentani. "FEM Modelling Approaches of Bolt Connections for the Dynamic Analyses of an Automotive Engine". Applied Sciences 11, n.º 10 (11 de mayo de 2021): 4343. http://dx.doi.org/10.3390/app11104343.
Texto completoResumen
Three different finite element method (FEM) modelling approaches of bolt connections of a four-stroke, four-cylinder petrol engine are presented, and the related results compared in terms of preprocessing time and accuracy. A full 3D modelling of the bolt connections was preliminarily validated through a comparison with experimental test data available for the whole engine. Two further modelling approaches, a 1D approach and a contact-based (0D) approach, were benchmarked considering their influence on the accuracy for the dynamic analysis of an engine. Each of the three approaches presented pros and cons, even if the 1D modelling could be envisaged as the recommended one in most of cases.
6
Altosole, M. y Massimo Figari. "Effective simple methods for numerical modelling of marine engines in ship propulsion control systems design". Journal of Naval Architecture and Marine Engineering 8, n.º 2 (30 de diciembre de 2011): 129–47. http://dx.doi.org/10.3329/jname.v8i2.7366.
Texto completoResumen
In the last year, the Department of Naval Architecture and Marine Engineering of Genoa University (now Department of Naval Architecture, Marine Technology and Electrical Engineering) collaborated to the design of the propulsion automation of two different naval vessels; within these projects the authors developed different ship propulsion simulators used to design and test the propulsion control schemes. In these time-domain simulators, each propulsion component is represented by a specific mathematical model, mainly based on algebraic and differential equations. One of the key aspects of the propulsion simulation is the engine dynamics. This problem in principle can be dealt with models based on thermodynamic principles, which are able to represent in detail the behaviour of many variables of interest (engine power and speed, air and gas pressures, temperatures, stresses, etc.). However, thermodynamic models are often characterized by a long computation-time and moreover their development usually requires the knowledge of specific engine information not always available. It is generally preferable to adopt simpler simulation models, for the development of which, very few kinds of information are necessary. In fact, for the rapid prototyping of control schemes, it is generally more important to model the whole plant (in a relatively coarse way) rather than the detailed model of some components. This paper deals with simple mathematical methods, able to represent the engine power or torque only, but they can be suitably applied to many types of marine engines in a straightforward way. The proposed simulation approaches derived from the authors’ experience, gained during their activity in the marine simulation field, and they are particularly suitable for a fast prototyping of the marine propulsion control systems. The validation process of these particular models, regarding a Diesel engine, a marine gas turbine and an electric motor, is illustrated based on the sea trials data and engine manufacturers’ data. Keywords: Dynamic simulation; marine engines performance; gas turbine; propulsion control. doi: http://dx.doi.org/10.3329/jname.v8i2.7366 Journal of Naval Architecture and Marine Engineering 8(2011) 129-147
7
Zhang, Sanhua, Kunhao Tang y Xinhong Zheng. "Modelling and optimal control of energy-saving-oriented automotive engine thermal management system". Thermal Science 25, n.º 4 Part B (2021): 2897–904. http://dx.doi.org/10.2298/tsci2104897z.
Texto completoResumen
The thesis simulates the engine?s installation and uses conditions in the whole vehicle, such as the water tank, fan, the engine?s arrangement in the engine room, accessories and pipe-line connections, etc. to build a test bench for the engine thermal management system. According to the thermal management simulation analysis software KULI modelling, the article designs the bench test conditions according to the parameter input requirements of the thermal management simulation analysis software. The accuracy of the model is verified by comparing simulation and test data, and the NEDC driving cycle is used to simulate the performance of the vehicle cooling system to guide the selection and matching of thermal management system components.
8
Rosli, M. Haziq Adham, M. Razali Hanipah y Maurice Kettner. "The tuning of a small four-stroke spark ignition engine for flexible valve timings through numerical approach". MATEC Web of Conferences 255 (2019): 04004. http://dx.doi.org/10.1051/matecconf/201925504004.
Texto completoResumen
Variable valve timing has been implemented by various manufacturers to improve internal combustion engine performance while operating at wide speed and load ranges. A novel flexible valve timing system for a small four-stroke engine is currently under development by Automotive Engineering Research Group (AERG) in Universiti Malaysia Pahang (UMP). In this paper, a comprehensive intake and exhaust tuning for the flexible variable valve timing is presented. A numerical assessment has been conducted through one dimensional engine modelling and simulation using validated model. There are eight valve timing configurations investigated for the tuning for three main speed regions. The simulation shows a positive and significant impact to the engine performance in three approaches; namely late intake valve closing, early intake valve closing and late exhaust valve closing. These approaches sufficiently covered the whole range of engine speeds for optimum engine operational performance.
9
Andreassi, L., S. Cordiner y V. Rocco. "Modelling the early stage of spark ignition engine combustion using the KIVA-3V code incorporating an ignition model". International Journal of Engine Research 4, n.º 3 (1 de junio de 2003): 179–92. http://dx.doi.org/10.1243/146808703322223379.
Texto completoResumen
The evolution of early stages of homogeneous mixture combustion in spark ignition (SI) engines represents a critical period that greatly affects the whole combustion process. A proper description of this critical phase represents a major issue, which could strongly influence the overall model predictive capability (i.e. model ability to reproduce the real engine behaviour for a large range of operating conditions without any major tuning). Such requirements become even more important for the simulation of last-generation gasoline direct injection or lean stratified engines, where ignition could determine the functionality of the engine itself. In this paper, after a detailed analysis of the ignition physical process and its modelling issues, the predictive capability of the KIVA-3V code has been improved by substituting the original ignition procedure with a more detailed kernel evolution model based on the one presented by Herweg and Maly in 1992. The ignition model introduced in a KIVA-3V version already modified by the authors (re-zoning algorithm, combustion and turbulence models, cylinder wall heat transfer, etc.) has then been tested in order to assess its level of accuracy in describing this complex phenomenon, by varying the most critical engine operating conditions and keeping combustion tuning parameters unchanged. After comparing ignition model results with the corresponding ones presented by Herweg and Maly, a specific application of the overall model (KIVA-3V + ignition model + turbulent combustion model) has been made to perform an analysis of a compressed natural gas (CNG) fuelled engine for heavy-duty applications. To this aim, the in-cylinder combustion history and the related processes as the temperature distribution and NOx formation have been calculated and verified with reference to the experimental data measured in a wide range of operating conditions of an IVECO turbocharged engine.
10
Siano, D. y R. Citarella. "Elastic Multi Body Simulation of a Multi-Cylinder Engine". Open Mechanical Engineering Journal 8, n.º 1 (13 de junio de 2014): 157–69. http://dx.doi.org/10.2174/1874155x01408010157.
Texto completoResumen
This paper analyzes the vibration behavior of an in-line 4-cylinder, 4-strokes, internal combustion turbocharged direct injection gasoline engine. A detailed multi-body numerical model of the engine prototype was used to characterize the whole engine dynamic behavior, in terms of forces and velocities. The crank train multi-body model was created starting from engine geometrical data, and the available combustion loads were employed for the Multi-Body Dynamic Simulation (MBDS). A combined usage of FEM and multi body methodologies were adopted for the dynamic analysis: both crankshaft and cylinder block were considered as flexible bodies, whereas all the other components were considered as rigid. The engine mounts were considered as flexible elements with given stiffness and damping. The hydrodynamic bearings were also modelling. The software LMS Virtual Lab (modules PDS and Motion) and ANSYS were used for the simulation.
11
Buyuksalih, I., S. Bayburt, G. Buyuksalih, A. P. Baskaraca, H. Karim y A. A. Rahman. "3D MODELLING AND VISUALIZATION BASED ON THE UNITY GAME ENGINE – ADVANTAGES AND CHALLENGES". ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences IV-4/W4 (13 de noviembre de 2017): 161–66. http://dx.doi.org/10.5194/isprs-annals-iv-4-w4-161-2017.
Texto completoResumen
3D City modelling is increasingly popular and becoming valuable tools in managing big cities. Urban and energy planning, landscape, noise-sewage modelling, underground mapping and navigation are among the applications/fields which really depend on 3D modelling for their effectiveness operations. Several research areas and implementation projects had been carried out to provide the most reliable 3D data format for sharing and functionalities as well as visualization platform and analysis. For instance, BIMTAS company has recently completed a project to estimate potential solar energy on 3D buildings for the whole Istanbul and now focussing on 3D utility underground mapping for a pilot case study. The research and implementation standard on 3D City Model domain (3D data sharing and visualization schema) is based on CityGML schema version 2.0. However, there are some limitations and issues in implementation phase for large dataset. Most of the limitations were due to the visualization, database integration and analysis platform (Unity3D game engine) as highlighted in this paper.
12
Yang, Liu, Kaili Liu, Yuan Zhong, Shirui Zhou, Beijing Cai y Xinyu Yang. "Optimization Study of Nacelle mounting position for Blended-Wing-Body Aircraft". Journal of Physics: Conference Series 2228, n.º 1 (1 de marzo de 2022): 012007. http://dx.doi.org/10.1088/1742-6596/2228/1/012007.
Texto completoResumen
Abstract Blended-wing-body aircraft is a new type of aircraft form that has been used in military aircraft. The potential for application in civil aircraft is being explored. Due to its special shape, the blended-wing-body aircraft is difficult to adopt the conventional under-wing engine mounting form, and usually applies the back braced mounting. The engine mounted on the back could cause surge and separation problems, which affects the flow field quality of the whole aircraft. In this paper, the effect of height and axial mounting position on the overall flow field of the aircraft is determined by modelling and calculation of the blended-wing-body aircraft. The effect of airflow separation is analysed. The engine axial mounting position is discovered to have a significant effect on the elimination of flow separation.
13
Tsentis, S. E., V. G. Gkoutzamanis, A. D. Gaitanis y A. I. Kalfas. "Multi-platform app-embedded model for hybrid air-breathing rocket-cycle engine in hypersonic atmospheric ascent". Aeronautical Journal 125, n.º 1291 (26 de febrero de 2021): 1631–53. http://dx.doi.org/10.1017/aer.2021.3.
Texto completoResumen
ABSTRACTThis paper presents a performance analysis on a novel engine concept, currently under development, in order to achieve hybrid air-breathing rocket technology. A component-level approach has been developed to simulate the performance of the engine at Mach 5, and the thermodynamic interaction of the different working fluids has been analysed. The bypass ramjet duct has also been included in the model. This facilitates the improved evaluation of performance parameters. The impact of ram drag induced by the intake of the engine has also been demonstrated. The whole model is introduced into a multi-platform application for aeroengine simulation to make it accessible to the interested reader. Results show that the bypass duct modelling increases the overall efficiency by approximately 7%. The model calculates the specific impulse at approximately 1800 seconds, which is 4 times higher than any chemical rocket.
14
Liu, Qiaobin, Wenku Shi y Zhiyong Chen. "Identification of firefly algorithm-based fluctuation coefficient of the exciting torque for vehicle driveline". Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics 233, n.º 2 (26 de octubre de 2018): 317–26. http://dx.doi.org/10.1177/1464419318808172.
Texto completoResumen
The unbalanced excitation force and torque generated by an engine that resonate with the natural frequency of drivetrain often causes vibration and noise problems in vehicles. This study aims to comprehensively employ theoretical modelling and experimental identification methods to obtain the fluctuation coefficients of engine excitation torque when a car is in different gear positions. The inherent characteristics of the system are studied on the basis of the four-degree-of-freedom driveline lumped mass model and the longitudinal dynamics model of vehicle. The correctness of the model is verified by torsional vibration test. The second order's engine torque fluctuation coefficients are identified by firefly algorithm according to the curves of flywheel speed in different gears under the acceleration condition of the whole open throttle. The torque obtained by parameter identification is applied to the model, and the torsional vibration response of the system is analysed. The influence of the key parameters on the torsional vibration response of the system is investigated. The study concludes that proper reduction of clutch stiffness can increase clutch damping and half-axle rigidity, which can help improve the torsional vibration performance of the system. This study can provide reference for vehicle drivetrain modelling and torsional vibration control.
15
Zhiyong, Gao, Li Jiwu y Wang Rongxi. "Prognostics uncertainty reduction by right-time prediction of remaining useful life based on hidden Markov model and proportional hazard model". Eksploatacja i Niezawodnosc - Maintenance and Reliability 23, n.º 1 (2 de enero de 2021): 154–65. http://dx.doi.org/10.17531/ein.2021.1.16.
Texto completoResumen
Uncertainty is a key problem in remaining useful life (RUL) prediction, and measures to reduce uncertainty are necessary to make RUL prediction truly practical. In this paper, a right-time prediction method is proposed to reduce the prognostics uncertainty of mechanical systems under unobservable degradation. Correspondingly, the whole RUL prediction process is divided into three parts, including offline modelling, online state estimating and online life predicting. In the offline modelling part, hidden Markov model (HMM) and proportional hazard model (PHM) are built to map the whole degradation path. During operation, the degradation state of the object is estimated in real time. Once the last degradation state reached, the degradation characteristics are extracted, and the survival function is obtained with the fitted PHM. The proposed method is demonstrated on an engine dataset and shows higher accuracy than traditional method. By fusing the extracted degradation characteristics, the obtained survival function can be basis for optimal maintenance with lower uncertainty.
16
Al-Hamdan, Qusai Z. y Munzer S. Y. Ebaid. "Modeling and Simulation of a Gas Turbine Engine for Power Generation". Journal of Engineering for Gas Turbines and Power 128, n.º 2 (27 de abril de 2005): 302–11. http://dx.doi.org/10.1115/1.2061287.
Texto completoResumen
The gas turbine engine is a complex assembly of a variety of components that are designed on the basis of aerothermodynamic laws. The design and operation theories of these individual components are complicated. The complexity of aerothermodynamic analysis makes it impossible to mathematically solve the optimization equations involved in various gas turbine cycles. When gas turbine engines were designed during the last century, the need to evaluate the engines performance at both design point and off design conditions became apparent. Manufacturers and designers of gas turbine engines became aware that some tools were needed to predict the performance of gas turbine engines especially at off design conditions where its performance was significantly affected by the load and the operating conditions. Also it was expected that these tools would help in predicting the performance of individual components, such as compressors, turbines, combustion chambers, etc. At the early stage of gas turbine developments, experimental tests of prototypes of either the whole engine or its main components were the only method available to determine the performance of either the engine or of the components. However, this procedure was not only costly, but also time consuming. Therefore, mathematical modelling using computational techniques were considered to be the most economical solution. The first part of this paper presents a discussion about the gas turbine modeling approach. The second part includes the gas turbine component matching between the compressor and the turbine which can be met by superimposing the turbine performance characteristics on the compressor performance characteristics with suitable transformation of the coordinates. The last part includes the gas turbine computer simulation program and its philosophy. The computer program presented in the current work basically satisfies the matching conditions analytically between the various gas turbine components to produce the equilibrium running line. The computer program used to determine the following: the operating range (envelope) and running line of the matched components, the proximity of the operating points to the compressor surge line, and the proximity of the operating points at the allowable maximum turbine inlet temperature. Most importantly, it can be concluded from the output whether the gas turbine engine is operating in a region of adequate compressor and turbine efficiency. Matching technique proposed in the current work used to develop a computer simulation program, which can be served as a valuable tool for investigating the performance of the gas turbine at off-design conditions. Also, this investigation can help in designing an efficient control system for the gas turbine engine of a particular application including being a part of power generation plant.
17
Pipitone, Emiliano, Salvatore Caltabellotta, Antonino Sferlazza y Maurizio Cirrincione. "Hybrid Propulsion Efficiency Increment through Exhaust Energy Recovery—Part 1: Radial Turbine Modelling and Design". Energies 16, n.º 3 (17 de enero de 2023): 1030. http://dx.doi.org/10.3390/en16031030.
Texto completoResumen
The efficiency of Hybrid Electric Vehicles (HEVs) may be substantially increased if the energy of the exhaust gases, which do not complete the expansion inside the cylinder of the internal combustion engine, is efficiently recovered by means of a properly designed turbogenerator and employed for vehicle propulsion; previous studies, carried out by the same authors of this work, showed a potential hybrid vehicle fuel efficiency increment up to 15% by employing a 20 kW turbine on a 100 HP rated power thermal unit. The innovative thermal unit here proposed is composed of a supercharged engine endowed with a properly designed turbogenerator, which comprises two fundamental elements: an exhaust gas turbine expressly designed and optimized for the application, and a suitable electric generator necessary to convert the recovered energy into electric energy, which can be stored in the on-board energy storage system of the vehicle. In these two parts, the realistic efficiency of the innovative thermal unit for hybrid vehicle is evaluated and compared to a traditional turbocharged engine. In Part 1, the authors present a model for the prediction of the efficiency of a dedicated radial turbine, based on a simple but effective mean-line approach; the same paper also reports a design algorithm, which, owing to some assumptions and approximations, allows a fast determination of the proper turbine geometry for a given design operating condition. It is worth pointing out that, being optimized for quasi-steady power production, the exhaust gas turbine considered is quite different from the ones commonly employed for turbocharging application; for this reason, and in consideration of the required power size, such a turbine is not available on the market, nor has its development been previously carried out in the scientific literature. In the Part 2 paper, a radial turbine geometry is defined for the thermal unit previously calculated, employing the design algorithm described in Part 1; the realistic energetic advantage that could be achieved by the implementation of the turbogenerator on a hybrid propulsion system is evaluated through the performance prediction model under the different operating conditions of the thermal unit. As an overall result, it was estimated that, compared to a reference traditional turbocharged engine, the turbocompound system could gain vehicle efficiency improvement between 3.1% and 17.9%, depending on the output power level, while an average efficiency increment of 10.9% was determined for the whole operating range.
18
Bazaras, Jonas. "INTERNAL NOISE MODELLING PROBLEMS OF TRANSPORT POWER EQUIPMENT". TRANSPORT 21, n.º 1 (31 de marzo de 2006): 19–24. http://dx.doi.org/10.3846/16484142.2006.9638035.
Texto completoResumen
The acoustic analysis of transport vehicles is presented in this article. Two types of vehicles of Russian production (TEP‐60 and M62) were selected for this research. Using ANSYS/Multiphysic software acoustic noise of different power units in the engine sector was simulated. In this paper we present the modelling results of the locomotive internal noise. In ANSYS/Multiphysic anbience the problems of acoustics are solved on the basis of harmonic response analysis by providing harmonic pressure excitation (sine type) at some points of fluid structure and obtaining the pressure distribution in the fluid. By changing the agitation frequency variable sound distribution at the interval of different frequencies is obtained. Constructing the calculation scheme for a three dimensional locomotive model, spatial structure of finite elements is used. The whole construction was described by 3D finite elements FLUID30 designed for a specified acoustic analysis. The presented acoustic calculation model of rolling‐stock cabin allows the evaluation of structural solutions and, in case of emergency, taking extra measures in the process of rolling‐stock design. The results of acoustic calculation were compared with experimental measurements.
19
Djilali, Kaid-Ameur y Mohamed Serrier. "Experimental Method of Tribological Modelling of Different Coatings of Stainless Steel". Mechanics and Mechanical Engineering 22, n.º 4 (2 de septiembre de 2020): 1273–86. http://dx.doi.org/10.2478/mme-2018-0098.
Texto completoResumen
AbstractFretting wear is a unique form of material degradation caused by small amplitude oscillatory relative motion of two surfaces in contact. Fretting wear is typically encountered at relative displacements of less than 300 μm and occurs in either a gross slip regime [1] (where there is slip displacement across the whole contact), or a partial slip regime (where there are parts of the contact where no slip displacement occurs). Fretting wear is experienced within a wide range of industrial sectors, [2] including aero engine couplings, locomotive axles and nuclear fuel casings [3]. Under higher loads and smaller displacement amplitudes, the contact will be within the partial slip regime, often resulting in fretting fatigue where the dominant damage mode is a reduction in fatigue life [4]. Friction is a very common phenomenon in daily life and industry, which is governed by the processes occurring in the thin surfaces layers of bodies in moving contact. The simple and fruitful idea used in studies of friction is that there are two main non-interacting components of friction, namely, adhesion and deformation [5, 6].
20
Hong, C. W. y C. C. Chen. "Dynamic performance simulation of a continuously variable transmission motorcycle for fuzzy autopilot design". Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 211, n.º 6 (1 de junio de 1997): 477–90. http://dx.doi.org/10.1243/0954407971526597.
Texto completoResumen
This paper describes the modelling technique of a continuously variable transmission (CVT) motorcycle for control strategy design of an autopilot on a driving cycle test bench. The simulation is carried out on a code which is the combination of an engine cycle simulation synthesis, a dynamic CVT driveline algorithm, a chassis dynamometer model and a fuzzy autopilot controller. The autopilot, which is a robot driver, includes a throttle actuator and a brake handle controller. Fundamental fuzzy theories were employed to simulate the control strategy of an experienced driver, also to form a feedback control loop for the simulation. The whole simulation package is capable of predicting the motorcycle performance under dynamic road conditions, such as ECE R40 and USA FTP75 driving patterns. Simulation results of a baseline motorcycle, equipped with a 125 cm3 four-stroke engine plus a rubber belt CVT system, are demonstrated in this paper. Parametric studies are used to design the control strategy of the autopilot as well as to improve the design of the powertrain system of the motorcycle.
21
Wojtowicz, Konrad, Wiesław Sobieraj y Bartosz Brzozowski. "Simulation Method of UAV Avionics System Designing". Solid State Phenomena 198 (marzo de 2013): 238–42. http://dx.doi.org/10.4028/www.scientific.net/ssp.198.238.
Texto completoResumen
Avionics system software development is a sophisticated process depended on not fully specified factors. Therefore, essential steps in the development process are tests and verification. In this aim the virtual environment was constructed and prepared for the tests with the target software and the hardware to eliminate hardware defects and software bugs before first flight. The concept of virtual environment was established and developed after unsuccessful flights with long term prepared aircraft models. There was assumed that modelling methods applied separately to frame, engine and control system were not sufficient. There was requirement for complex simulation platform prepared to test whole aircraft in various environment conditions. In the first step the designing process was identified and milestones were placed inside (Fig. 1)
22
Buyuksalih, G., S. Bayburt, A. P. Baskaraca, H. Karim y A. Abdul Rahman. "CALCULATING SOLAR ENERGY POTENTIAL OF BUILDINGS AND VISUALIZATION WITHIN UNITY 3D GAME ENGINE". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-4/W5 (5 de octubre de 2017): 39–44. http://dx.doi.org/10.5194/isprs-archives-xlii-4-w5-39-2017.
Texto completoResumen
Solar energy modelling is increasingly popular, important, and economic significant in solving energy crisis for big cities. It is a clean and renewable resource of energy that can be utilized to accommodate individual or group of buildings electrical power as well as for indoor heating. Implementing photovoltaic system (PV) in urban areas is one of the best options to solve power crisis over expansion of urban and the growth of population. However, as the spaces for solar panel installation in cities are getting limited nowadays, the available strategic options are only at the rooftop and façade of the building. Thus, accurate information and selecting building with the highest potential solar energy amount collected is essential in energy planning, environmental conservation, and sustainable development of the city. Estimating the solar energy/radiation from rooftop and facade are indeed having a limitation - the shadows from other neighbouring buildings. The implementation of this solar estimation project for Istanbul uses CityGML LoD2-LoD3. The model and analyses were carried out using Unity 3D Game engine with development of several customized tools and functionalities. The results show the estimation of potential solar energy received for the whole area per day, week, month and year thus decision for installing the solar panel could be made. We strongly believe the Unity game engine platform could be utilized for near future 3D mapping visualization purposes.
23
Bolu, Gabriel, Gareth Pierce, Anthony Gachagan, Tim Barden y Gerald Harvey. "Investigations into the Vibrational Response of an Aero-Engine Turbine Blade under Thermosonic Excitation". Key Engineering Materials 518 (julio de 2012): 184–92. http://dx.doi.org/10.4028/www.scientific.net/kem.518.184.
Texto completoResumen
Thermosonics is a rapid and potentially cost-saving non-destructive testing (NDT) screening technique that can be applied to the identification of cracks in high pressure compressor turbine blades in turbofan engines. The reliability of the thermosonic technique is not well established for inspecting these complex components; in particular the vibrational energy generated within a component during a thermosonic test is often highly non-uniform, leading to the possibility of missing critical defects. The aim of this study was to develop a methodology, using a combination of vibration measurements and finite element analysis (FEA), to model the vibrational energy within a turbine blade in a typical thermosonic inspection scenario. Using a laser vibrometer, the steady-state vibration response (i.e. frequency response) at several locations on a blade was measured and used to identify the prominent peaks in the frequency spectra. These were then used to generate an excitation function for the finite element modelling approach. Acceptable correlation between the measured and simulated vibration response at a number of specific locations on the blade allowed the forcing function to simulate the vibration response across the whole blade. Finally, the predicted displacement field was used to determine the vibrational energy at every point on the blade which was mapped onto a CAD representation of the blade, thereby highlighting areas on the blade that were below the defect detection threshold.
24
Pachidis, Vassilios, Pericles Pilidis, Ioannis Templalexis, Theodosios Korakianitis y Petros Kotsiopoulos. "Prediction of Engine Performance Under Compressor Inlet Flow Distortion Using Streamline Curvature". Journal of Engineering for Gas Turbines and Power 129, n.º 1 (1 de febrero de 2006): 97–103. http://dx.doi.org/10.1115/1.2363414.
Texto completoResumen
Traditionally, engine performance has been simulated based on nondimensional maps for compressors and turbines. Component characteristic maps assume by default a given state of inlet conditions that cannot be easily altered in order to simulate two- or three-dimensional flow phenomena. Inlet flow distortion, for example, is usually simulated by applying empirical correction factors and modifiers to default component characteristics. Alternatively, the parallel compressor theory may be applied. The accuracy of the above methods has been rather questionable over the years since they are unable to capture in sufficient fidelity component-level, complex physical processes and analyze them in the context of the whole engine performance. The technique described in this paper integrates a zero-dimensional (nondimensional) gas turbine modelling and performance simulation system and a two-dimensional, streamline curvature compressor software. The two-dimensional compressor software can fully define the characteristics of any compressor at several operating conditions and is subsequently used in the zero-dimensional cycle analysis to provide a more accurate, physics-based estimate of compressor performance under clean and distorted inlet conditions, replacing the default compressor maps. The high-fidelity, two-dimensional compressor component communicates with the lower fidelity cycle via a fully automatic and iterative process for the determination of the correct operating point. This manuscript firstly gives a brief overview of the development, validation, and integration of the two-dimensional, streamline curvature compressor software with the low-fidelity cycle code. It also discusses the relative changes in the performance of a two-stage, experimental compressor with different types of radial pressure distortion obtained by running the two-dimensional streamline curvature compressor software independently. Moreover, the performance of a notional engine model, utilizing the coupled, two-dimensional compressor, under distorted conditions is discussed in detail and compared against the engine performance under clean conditions. In the cases examined, the analysis carried out by this study demonstrated relative changes in the simulated engine performance larger than 1%. This analysis proves the potential of the simulation strategy presented in this paper to investigate relevant physical processes occurring in an engine component in more detail, and to assess the effects of various isolated flow phenomena on overall engine performance in a timely and affordable manner. Moreover, in contrast to commercial computational fluid dynamics tools, this simulation strategy allows in-house empiricism and expertise to be incorporated in the flow-field calculations in the form of deviation and loss models.
25
Qian, Fu y Zhang Shensheng. "Product Development Process Management System Based on P_PROCE Model". Concurrent Engineering 10, n.º 3 (septiembre de 2002): 203–11. http://dx.doi.org/10.1177/106329302761689124.
Texto completoResumen
Product data management (PDM) systems are enabling tool of concurrent engineering (CE). Although the PDM system provides good support for product data, particularly at the early stages of design, it is seldom used beyond the design process. Furthermore, it provides few facilities for activity definition and no facilities for the enactment of production activities. In order to manage the whole lifecycle of motorcycle development, this paper presents a product development process management system that integrates the workflow management system (WFMS) with the PDM. On one hand we can use the powerful product data management functionality of PDM systems, on the other hand we can use the effective process management and control functionalities of WFMS. For the sake of guiding and constraining the workflow modeling, we provide an integrated product development workflow model named P_PROCE model. It is made up of five views that are the process view(P), the product view(P), the resource view(R), and the organization view(O), the control & evaluation view(CE). Based on this model, the architecture and implementation of the product development process management system is presented. It consists of the workflow modeling module, the workflow enactment module and the PDM system. The first module includes process modeling, system sustain and API. The second module includes the personal desktop and the workflow engine. The PDM system is regarded as a workflow-enabled application. The workflow engine invokes it by the Tool Agent.
26
Costa, Michela, Gaia Martoriello y Raffaele Tuccillo. "Modelling of an innovative and autonomous micro-grid based on a biomass - solar PV hybrid power system". E3S Web of Conferences 238 (2021): 02003. http://dx.doi.org/10.1051/e3sconf/202123802003.
Texto completoResumen
Micro-Combined heat and power (m-CHP) systems fuelled by renewables, such as residual biomasses, are today of great interest to produce energy in an efficient and green way. The aim of the present work is to develop a numerical model of a hybrid energy system including a biomass powered m-CHP unit based on gasification and coupled with solar photovoltaic (PV) modules and to an electrical storage device, able to provide energy to remote areas. Main advantages of the considered configuration are its ultra-low environmental impact and just its autonomous operation by local resources. The developed unsteady multiphysical model accounts for the main plant components, namely the syngas powered engine, the PV panels and the battery, as well for a dynamic use of the produced energy. Main features of the adopted schematization of the actual system rely on the proper description of syngas combustion, that takes into account the extreme difficulty of working with a non-conventional gas, and on a PID control that is considered for energy flow management to meet the electrical demand curve. The PV panel current is calculated through an ad-hoc function that reads, at any given time, actual solar irradiance data in the city of Naples, Italy, the battery voltage and the main parameters of the PV module. The battery, with a voltage of 48V and a capacity of 100kWh, is modelled as an equivalent circuit with its proper State of Charge (SoC) versus Open Circuit Voltage (OCV) curve. The voltage response to a current at a particular SoC and temperature are calculated. This dynamic modelling permits the optimal control of the whole system to meet the electrical and thermal user’s demand and also to better design any possible change in the storage or PV size to meet specific real uses of the produced energy.
27
Fois, N., M. Watson y MB Marshall. "The influence of material properties on the wear of abradable materials". Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 231, n.º 2 (5 de agosto de 2016): 240–53. http://dx.doi.org/10.1177/1350650116649528.
Texto completoResumen
In aero-engines it is possible for the blades of the compressor, turbine or fan to incur into their casings. At these interfaces a lining of composite abradable material is used to limit damage to components and thereby sustain the efficiency and longevity of the engine as a whole. These composite materials must have good abradability and erosion resistance. Previously, the wear mechanisms at the contact between the blade and the coating have been characterised using stroboscopic imaging and force measurement on a scaled test-rig platform. This work is focused on the characterisation of the wear mechanism for two different hardnesses of abradable lining. The established stroboscopic imaging technique and contact force measurements are combined with sectioning of the abradable material in order to analyse the material’s response during the tests. A measure of the thermal properties and the resulting temperature of the linings during the test have also been made to further understand the effect of coating hardness. The wear mechanism, material response, contact force and thermal properties of the coating have been used to characterise the different material behaviour with different hardness. At low incursion rates, with a soft coating, the blade tip becomes worn after an initial adhesive transfer from the coating. Post-test sectioning showed blade material and significant compaction present in the coating. The harder coating produced adhesion on the blade tip with solidification observed in the coating. Thermal diffusivity measurements and modelling indicated that thermally driven wear observed was as a consequence of the increased number of boundaries between the metal and hBN phases present interrupting heat flow, leading to a concentration of surface heat. At higher incursion rates, the wear mechanism is more similar between the coatings and a cutting mechanism dominates producing negligible adhesion and blade wear.
28
Thompson, G. J., C. M. Atkinson, N. N. Clark, T. W. Long y E. Hanzevack. "Technical Note: Neural network modelling of the emissions and performance of a heavy-duty diesel engine". Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 214, n.º 2 (1 de febrero de 2000): 111–26. http://dx.doi.org/10.1177/095440700021400201.
Texto completoResumen
Internal combustion engines are being required to comply with increasingly stringent government exhaust emissions regulations. Compression ignition (CI) piston engines will continue to be used in cost-sensitive fuel applications such as in heavy-duty buses and trucks, power generation, locomotives and off-highway applications, and will find application in hybrid electric vehicles. Close control of combustion in these engines will be essential to achieve ever-increasing efficiency improvements while meeting increasingly stringent emissions standards. The engines of the future will require significantly more complex control than existing map-based control strategies, having many more degrees of freedom than those of today. Neural network (NN)-based engine modelling offers the potential for a multidimensional, adaptive, learning control system that does not require knowledge of the governing equations for engine performance or the combustion kinetics of emissions formation that a conventional map-based engine model requires. The application of a neural network to model the output torque and exhaust emissions from a modern heavy-duty diesel engine (Navistar T444E) is shown to be able to predict the continuous torque and exhaust emissions from a heavy-duty diesel engine for the Federal heavy-duty engine transient test procedure (FTP) cycle and two random cycles to within 5 per cent of their measured values after only 100 min of transient dynamometer training. Applications of such a neural net model include emissions virtual sensing, on-board diagnostics (OBD) and engine control strategy optimization.
29
Pylypenko, O. V., O. O. Prokopchuk, S. I. Dolgopolov, O. D. Nikolayev, N. V. Khoriak, V. Yu Pysarenko, I. D. Bashliy y S. V. Polskykh. "Mathematical modelling of start-up transients at clustered propulsion system with POGO-suppressors for CYCLON-4M launch vehicle". Kosmìčna nauka ì tehnologìâ 27, n.º 6 (2021): 3–15. http://dx.doi.org/10.15407/knit2021.06.003.
Texto completoResumen
Liquid-propellant rocket propulsion systems of the first stages of launch vehicles of medium, heavy, and super-heavy class usually include POGO-suppressors, which are one of the most widely used methods to eliminate launch vehicle longitudinal structural vibrations (POGO phenomena). However, until now, the theoretical studies and analysis of the effect of the POGO-suppressors’ installation in the feedlines of main liquid rocket engines on transient processes in systems during rocket engine starting have not been carried out due to the complexity of such analysis and the lack, first of all, reliable nonlinear models of cavitation phenomena in rocket engine pumps. A mathematical model for the start-up of a clustered rocket propulsion of the Cyclone-4M launch vehicle has been developed that takes into account the low-frequency dynamics of the POGO-suppressors and the asynchronous start-up timeline sequences of the rocket engines. The first stage of the launch vehicle propulsion system includes four RD-870 rocket engines. A nonlinear mathematical model of low-frequency dynamic processes of the POGO-suppressor with bellows separation of liquid and gaseous media is presented. A significant effect of cavitation in the pumps of engines and the POGO-suppressor installation to the LOX feedline on the propulsion system dynamic gains is shown. Based on the developed mathematical model of the clustered rocket propulsion start-up, the studies of the Cyclone-4M main engines’ start-up transients were carried out. The asynchronous start-up timeline sequences of the rocket engine and the places of installation of the POGO-suppressors in the LOX feedline branches to the RD-870 rocket engine – near the general feedline collector as standard placement or directly at the entrance to the engines – were investigated. The analysis of start-up transients in the oxidizer feed system of the considered propulsion (the time dependences of the flowrate and pressure at the engine inlet) showed the following. Firstly, while the synchronous start-up of the engines, the installation of the POGO-suppressors near the feedline collector makes it possible to eliminate all engine inlet overpressures that exist in the rocket propulsion system in case of the absence of the POGO-suppressors. Secondly, the RD-870 engine asynchronous start-up operation affects negatively the time dependences of the propellant flowrate and pressure at the engine inlet if the POGO-suppressors are located near the feedline collector. So, in the propulsion system’s start-up timeline interval 0.95 s - 1.35 s, for some computational variants of the initial moments of the engine operation start, an abnormally large drop in the LOX flow rate and the overpressures at the engine inlet is observed. The asynchronous start-up of the RD-870 engines with the installation of the POGO-suppressors at the engine inlet does not significantly change the start-up transients compared to the synchronous starting of the engines. Thirdly, thus, it is shown that the installation of the POGO-suppressors both at the engine inlet and at the RD-870 branches near the collector has a significant positive effect on the quality of start-up transient processes for the main engines of the 1st stage of the Cyclone-4M launch vehicle. Placing the POGO-suppressors at the engine inlets is not standard and is considered without reference to the propulsion system layout. Nevertheless, the POGO-suppressors installed at the inlet to the engines are an effective means of preventing overshoots and dips in the parameters of the liquid-propellant rocket engine, including the conditions of asynchronous starting of the liquid rocket engines in the clustered propulsion system. The results obtained can be used in mathematical modeling of the start-up of the first stage propulsion system either for multistage sustainer rockets used in parallel with booster rockets or for the clustered multi-engine rocket propulsion system containing POGO-suppressors.
30
Kulmanakov, Sergey P., Sergejus Lebedevas, Sergey S. Kulmanakov, Nadežda Lazareva y Paulius Rapalis. "COMPARATIVE STUDIES OF THE BIODIESEL FUEL JET DEVELOPMENT DYNAMICS IN COMMON RAIL AND CONVENTIONAL DESIGN FUEL SYSTEMS". Transport 34, n.º 1 (31 de enero de 2019): 67–74. http://dx.doi.org/10.3846/transport.2019.7223.
Texto completoResumen
The results of comparative diesel and biodiesel (Rapeseed oil Methyl Ester (RME) and Rapeseed Oil (RO)) fuel jet structure studies by optical scanning method are presented. There is an interrelation between the dynamics of fuel jet development by the Common Rail (CR) with single-phase injection and Conventional Design System (CDS) and the parameters of mixture formation, which are typical for transferring the operation of the Diesel Engine (DE) from mineral diesel to RME and RO. The structure of the Diesel Fuel (DF) jet is significantly more heterogeneous by the size and number of droplets in CDS in comparison with CR. From the moment of the injection the presence of zones less saturated with fuel contributes to a relatively short induction period – 5° ca. compared to 11…12° ca. in the CR system. Using RME in the CR system in comparison with DF, increases the heterogeneity of the fuel jet, thereby causing a shorter (by 1…2° ca.) induction period in the whole investigated range of injection pressures of 60…160 MPa. The injection of a non-heated RO is accompanied by the shape and structure fluctuations of the fuel jet. RO heating to 65 °C stabilizes the structure of the jet and increases the share of less saturated zones. Promising way of use for the optical scanning method in the mathematical modelling of the DE working process is proposed.
31
Hasanovich, Linda y David Nobes. "Investigation of effect of heat exchanger size on power output in low-temperature difference Stirling engines". E3S Web of Conferences 313 (2021): 03002. http://dx.doi.org/10.1051/e3sconf/202131303002.
Texto completoResumen
The Stirling engine is capable of converting any source of thermal energy into kinetic energy, which makes it an attractive option for utilizing low-temperature sources such as geothermal or waste heat below 100 °C. However, at these low temperatures, the effects of losses are proportionally higher due to the lower thermal potential available. One such significant loss is excess dead volume, wherein a significant contributor is the heat exchangers. The heat exchangers must be selected to optimize power output by minimizing the dead volume loss while maximizing the heat transfer to and from the engine. To better understand what the optimal geometry of the heat exchanger components is, a Stirling engine is modelled using a third-order commercial modelling software (Sage) and trends of engine properties of power, temperature, and pressure for different heat exchanger geometries are observed. The results indicate that there is an optimum heat exchanger volume and geometry for low temperature Stirling engines. This optimum is also affected by other engine properties, such as regenerator size and engine speed. These results provide insight into the optimal geometry of these components for low-temperature Stirling engines, as well as providing design guidance for future engines to be built.
32
Mabrouk, M. B., A. Jonoski, D. Solomatine y S. Uhlenbrook. "A review of seawater intrusion in the Nile Delta groundwater system – the basis for assessing impacts due to climate changes and water resources development". Hydrology and Earth System Sciences Discussions 10, n.º 8 (19 de agosto de 2013): 10873–911. http://dx.doi.org/10.5194/hessd-10-10873-2013.
Texto completoResumen
Abstract. Serious environmental problems are emerging in the River Nile basin and its groundwater resources. Recent years have brought scientific evidence of climate change and development-induced environmental impacts globally as well as over Egypt. Some impacts are subtle, like decline of the Nile River water levels, others are dramatic like the salinization of all coastal land in the Nile Delta – the agricultural engine of Egypt. These consequences have become a striking reality causing a set of interconnected groundwater management problems. Massive population increase that overwhelmed the Nile Delta region has amplified the problem. Many researchers have studied these problems from different perspectives using different methodologies, following different objectives and, consequently, arrived at different findings. However, they all confirmed that significant groundwater salinization has affected the Nile Delta and this is likely to become worse rapidly in the future. This article presents, categorizes and critically analyses and synthesizes the most relevant research regarding climate change and development challenges in relation to groundwater resources in the Nile Delta. It is shown that there is a gap in studies that focus on sustainable groundwater resources development and environmentally sound protection as an integrated regional process in Nile Delta. Moreover, there is also a knowledge gap related to the deterioration of groundwater quality. The article recommends further research that covers the groundwater resources and salinization in the whole Nile Delta based on integrated three-dimensional groundwater modelling of the Nile delta aquifer.
33
Alkan, Selcuk y Tuba Ada. "Digital game design on the subject of identities and expansions". New Trends and Issues Proceedings on Humanities and Social Sciences 4, n.º 9 (11 de enero de 2018): 17–21. http://dx.doi.org/10.18844/prosoc.v4i9.3038.
Texto completoResumen
This study aimed to design a digital game used in the teaching of identities and expansions and provide modelling by students. This game was designed according to the eighth-grade math curriculum. Unity3d game engine was used in designing the game. The software required to run the game was written by researchers using C# and java script. At the stage of designing, initially, the game was introduced to five mathematics teachers and various arrangements were made according to their opinions. Then, the game was evaluated and given the final form by two instructors who were experts in the field of mathematics education. In general, problems was designed that can be solved by dividing the rectangle given by 2 dimensional and given one edge like (ax + b) into the sub rectangles such as x^2, 2x and 1 and by writing the final result of how many sub-rectangles formed the whole rectangle. The teachers who participated in the evaluation of the game stated that the game was suitable for education and the students would gain interest in the game during the course. Teachers have criticised the game only on visual matters. For education to be more effective, the number of such games and materials should be increased. For design of more effective and more interesting games, we must collaborate with the experts in the field of fine arts. Keywords: digital game; game; expansions; mathematics education
34
Crossland, R., J. Sims Williams y C. McMahon. "The practical application of design risk assessment models". Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 217, n.º 2 (1 de febrero de 2003): 227–34. http://dx.doi.org/10.1243/095440503321148867.
Texto completoResumen
This paper describes three case studies of the application of quantitative design risk assessment methods in practice. The studies arose out of a survey of risk practice in design which showed that leading edge companies use quantitative methods of risk assessment in assessing both project risk, which may be defined as the risk to cost and time-scale, and technical risk, which may be defined as the risk that the designed artefact will not meet its functional requirements. The first case study concerns a coastal defence programme and is primarily concerned with technical risk. The second study is concerned with the installation of a replacement bridge and is primarily concerned with project risk. The final study describes an aerospace engine design programme that involved both technical and project risks The paper first presents a generic overview of the risk management process and then describes, for each of the three study domains, how risk is identified, how risk assessment is carried out, including prioritization and uncertainty modelling, what risk treatment steps are undertaken and how risks are monitored. Outcomes in the three studies are shown to be a whole-life cost-benefit uncertainty model for assessing design alternatives, a method for incorporating uncertainty into task criticality as well as task duration in the activity network for a design project and a method for aggregating uncertainty in design attributes over the basic product model.
35
Wittig, S., S. Kim, Th Scherer y I. Weissert. "Numerical Study for Optimizing Heat Transfer in High Speed Rotating Components". International Journal of Rotating Machinery 4, n.º 3 (1998): 151–61. http://dx.doi.org/10.1155/s1023621x9800013x.
Texto completoResumen
Cooling of high speed rotating components is a typical situation found in turbomachinery as well as in automobile engines. Accurate knowledge of discharge coefficients and heat transfer of related components is essential for the high performance of the whole engine. This can be achieved by minimized cooling air flows and avoidance of hot spots. In high speed rotating clutches for example aerodynamic investigations improving heat transfer have not been considered in the past. Advanced concepts of modern plate design try to reduce thermal loads by convective cooling methods. Therefore, secondary cooling air flows have to be enhanced by an appropriate design of the rotor stator system with orifices. CFD modelling is used to improve the basic understanding of the flow field in typical geometries used in these systems.The computational results are obtained by a 3-D-finite-volume-code based on body fitted structured grids. The Navier Stokes equations are solved by a pressure-correction method combined with the standard k-e-turbulence model. Considering the rotation of orifices in disks or shafts, the frame of reference has to be changed to the rotating system. The flow through orifices in high speed rotating disks can be calculated with a high level of accuracy in comparison with experiments as shown in Wittig et al. [1994].Numerical results of the flow in a high speed rotating system are presented with emphasis on geometrical variations. Calculations are carried out in order to find an optimum design in terms of position and size of the orifices in the housing. These variations induce different physical phenomena. Special consideration is directed towards the basic problems of the flow through orifices in high speed rotating disks and shafts and the flow inside rotor-stator systems. As expected, the very complex flow fields are dominated by rotational effects. In addition it is shown that differences occur between the configuration of optimized mass flow rate and the geometry with a maximum of total heat transfer. Obviously, optimization procedures are dependent on the knowledge of the local flow field and cannot be performed without advanced CFD-methods. It is demonstrated that the approach presented here is suitable for these tasks.
36
Buhammood, A. H., Henry Abanda, Peter Garstecki, M. B. Manjia, Chrispin Pettang y Abdulrasheed Madugu Abdullahi. "Coupling BIM and Game Engine Technologies for Construction Knowledge Enhancement". International Journal of Gaming and Computer-Mediated Simulations 12, n.º 4 (octubre de 2020): 38–63. http://dx.doi.org/10.4018/ijgcms.2020100103.
Texto completoResumen
Interactions and collaboration between parties in construction projects are often characterised by misunderstandings and poor information exchange. Game engine technologies, when employed with building information modelling (BIM), can help address these shortcomings. Quite often, the visualisation capabilities of BIM models are not explored fully partly because of their limited interactive capability. While game engines are powerful in visualisation and interactions in the gaming industry, the literature suggests a lack of understanding of the applicability of the same in construction. This study investigates the potential of the use of game engines in construction practice which culminated in a framework that can guide the implementation of the same in enhancing interactive building walkthroughs.
37
Zalina Mat Nawi, Siti Kartom Kamarudin y Siti Rozaimah Sheikh Abdullah. "Improve Waste Heat Recovery and Performance of Organic Rankine Cycle Analysis for Exhaust Gas from A Marine Diesel Engine Using Biofuel from Algae". Journal of Advanced Research in Applied Sciences and Engineering Technology 29, n.º 3 (8 de febrero de 2023): 1–20. http://dx.doi.org/10.37934/araset.29.3.120.
Texto completoResumen
Marine diesel engines are commonly used as a propulsion system in ships. The waste heat generated from marine diesel engines is one of the key disadvantages of this system. This study aims to improve the recovery of waste heat generation. It presents the performance analysis of Organic Rankine Cycle (ORC) for exhaust gas in a marine diesel engine using different types of biofuels production methods from selected microalgae via mathematical modelling. The microalgae are from species of Synechococcus PCC 7002, Nannochloropsis oculata sp, Chlorella protothecoides, and Dunaliella sp. A marine engine with an exhaust gas of 9086.61 kg-h-1 is taken as a case study. While the conventional diesel engine has a performance efficiency of 30-40% with a power output of 35-200K, this study has indicated that the marine diesel engine in the ORC via biofuel from algae shows higher performance at approximately 51% with a net power output of approximately 160kW obtained for each biofuel. Later, the thermal efficiency of the ORC system with exhaust gas from the marine diesel engine as waste heat recovery is improved to 61% with a net power output of approximately 353kW after the heat integration. Biodiesel presents the highest mass flow rate (1.12 kg-s-1) compared to others. This study proved that biofuel from microalgae can achieve the highest performance in the ORC system with the lowest mass flow rate of biofuel compared to those in conventional fuel.
38
Hashchuk, P. y S. Nikipchuk. "HARD-SOFT TECHNOLOGY OF INFORMATION SUSPENSION PROCESS OF MODELING OF HEAT GENERATION/HEAT CONSUMPTION IN THE INTERNAL COMBUSTION ENGINE". Bulletin of Lviv State University of Life Safety, n.º 18 (31 de diciembre de 2018): 6–22. http://dx.doi.org/10.32447/20784643.18.2018.01.
Texto completoResumen
Deterministic and, in a certain sense, "linear" interpretation of the world often leads to the recognition of the fact that the more accurate model we need, the more complex it must be (as in case of a formalized reproduction of the real system, or the implementation of the desired system properties in the process of formal synthesis of something new). Instead, following the principle of synergy leads to the conviction that there is always a certain model of optimal complexity e.g. in the synthesis of the new system, and in the analysis of real system peculiarities. However, the model of reality could be a part of this reality that is included to the carefully structured formal description. Since we cannot penetrate into the working space of the serial engine while testing, we should use a test engine of a special construction when the working space corresponds to the laws of similarity and this engine will serve as a model of the working space of the serial engine.
The study illustrates the effectiveness of hard-soft technology while investigating the peculiarities of heat generation and heat consumption in the internal combustion engine, which will combine mathematic and algorithmic means of modelling as well as the means of real simulation. The necessity of hard-soft technology introduction arises from the excessive complexity of thermal phenomena occurring in the internal combustion engine (ICE), and the inability to fully subordinate these phenomena to existing analytical models.
The combination of original and analytical properties, reality and virtual reality while modelling the processes in internal combustion engines allows us to substantially improve the quality of information in the process of design and engine construction. Taking this into consideration, there are some natural grounds to apply principles of heuristic self-organization, self-learning, means of the neural networks, etc. in the design implementation.
The study demonstrates the example of modelling the real working space of ICE with the forced start that serves as a supplement to the mathematical algorithmic two-zone model of heat generation / heat consumption / heat extraction.
The basic information that can be obtained by means of hard-soft technology in the framework of, for example, the two-zone model of the work process in the gasoline engine, is the variability with the change in the angle of rotation of the crankshaft of the engine: absolute pressure (indicative diagram); absolute temperature; heat transmitted inside the cylinder between zones; coefficient of excess air; coefficient of heat transfer; intensity of heat extraction in the process of combustion of fuel; intensity of heat transfer through the walls of the cylinde
39
Molina, Santiago, Ricardo Novella, Josep Gomez-Soriano y Miguel Olcina-Girona. "New Combustion Modelling Approach for Methane-Hydrogen Fueled Engines Using Machine Learning and Engine Virtualization". Energies 14, n.º 20 (16 de octubre de 2021): 6732. http://dx.doi.org/10.3390/en14206732.
Texto completoResumen
The achievement of a carbon-free emissions economy is one of the main goals to reduce climate change and its negative effects. Scientists and technological improvements have followed this trend, improving efficiency, and reducing carbon and other compounds that foment climate change. Since the main contributor of these emissions is transportation, detaching this sector from fossil fuels is a necessary step towards an environmentally friendly future. Therefore, an evaluation of alternative fuels will be needed to find a suitable replacement for traditional fossil-based fuels. In this scenario, hydrogen appears as a possible solution. However, the existence of the drawbacks associated with the application of H2-ICE redirects the solution to dual-fuel strategies, which consist of mixing different fuels, to reduce negative aspects of their separate use while enhancing the benefits. In this work, a new combustion modelling approach based on machine learning (ML) modeling is proposed for predicting the burning rate of different mixtures of methane (CH4) and hydrogen (H2). Laminar flame speed calculations have been performed to train the ML model, finding a faster way to obtain good results in comparison with actual models applied to SI engines in the virtual engine model framework.
40
Camus, Benjamin, Thomas Paris, Julien Vaubourg, Yannick Presse, Christine Bourjot, Laurent Ciarletta y Vincent Chevrier. "Co-simulation of cyber-physical systems using a DEVS wrapping strategy in the MECSYCO middleware". SIMULATION 94, n.º 12 (26 de enero de 2018): 1099–127. http://dx.doi.org/10.1177/0037549717749014.
Texto completoResumen
Most modeling and simulation (M&S) questions about cyber-physical systems (CPSs) require expert skills belonging to different scientific fields. The challenges are then to integrate each domain’s tools (formalism and simulation software) within the rigorous framework of M&S process. To answer this issue, we give the specifications of the Multi-agent Environment for Complex-SYstem CO-simulation (MECSYCO) middleware which enables to interconnect several pre-existing and heterogeneous M&S tools, so they can simulate a whole CPS together. The middleware performs the co-simulation in a parallel, decentralized, and distributable fashion thanks to its modular multi-agent architecture. In order to rigorously integrate tools that use different formalisms, the co-simulation engine of MECSYCO is based on the discrete event system specification (DEVS). The central idea of MECSYCO is to use a DEVS wrapping strategy to integrate each tool into the middleware. Thus, heterogeneous tools can be homogeneously co-simulated in the form of a DEVS system. By using DEVS, MECSYCO benefits from the numerous scientific works which have demonstrated the integrative power of this formalism and give crucial guidelines to rigorously design wrappers. We demonstrate that our discrete framework can integrate a vast amount of continuous M&S tools by wrapping the Functional Mockup Interface (FMI) standard. To this end, we take advantage of DEVS efforts of the literature (namely, the DEV&DESS hybrid formalism and Quantized State System (QSS) solvers) to design DEVS wrappers for Functional Mockup Unit (FMU) components. As a side-effect, this wrapping is not restricted to MECSYCO but can be applied in any DEVS-based platform. We evaluate MECSYCO with the proof of concept of a smart heating use case, where we co-simulate non-DEVS-centric M&S tools.
41
Altosole, Marco, Ugo Campora, Massimo Figari, Michele Laviola y Michele Martelli. "A Diesel Engine Modelling Approach for Ship Propulsion Real-Time Simulators". Journal of Marine Science and Engineering 7, n.º 5 (11 de mayo de 2019): 138. http://dx.doi.org/10.3390/jmse7050138.
Texto completoResumen
A turbocharged diesel engine numerical model, suitable for real-time ship manoeuvre simulation, is presented in this paper. While some engine components (mainly the turbocharger, intercooler and manifolds) are modelled by a filling and emptying approach, the cylinder simulation is based on a set of five-dimensional numerical matrices (each matrix is generated by means of a more traditional thermodynamic model based on in-cylinder actual cycle). The new cylinder calculation approach strongly reduces the engine transient computation time, making it possible to transform the simulation model into a real-time executable application. As a case study, the simulation methodology is applied to a high speed four stroke turbocharged marine diesel engine, whose design and off design running data are available from the technical sheet. In order to verify the suitability of the proposed model in real-time simulation applications, a yacht propulsion plant simulator is developed. Numerical results in ship acceleration and deceleration manoeuvres are shown, reducing the simulation running time of 99% in comparison with the corresponding in-cylinder actual cycle engine model.
42
Ali, F., K. Tzanidakis, I. Goulos, V. Pachidis y R. d’Ippolito. "Multidisciplinary design and optimisation of conceptual rotorcraft powerplants for operational performance and environmental impact". Aeronautical Journal 119, n.º 1217 (julio de 2015): 891–914. http://dx.doi.org/10.1017/s0001924000010976.
Texto completoResumen
AbstractThis paper demonstrates the application of an integrated rotorcraft multidisciplinary design and optimisation framework, deployed for the purpose of preliminary design and assessment of optimum regenerative powerplant configurations for rotorcraft applications. The proposed approach comprises a wide-range of individual modelling theories applicable to rotorcraft flight dynamics, gas turbine engine performance and weight estimation as well as a physics-based stirred reactor model, for the rapid estimation of various gas turbine gaseous emissions. A single-objective Particle Swarm Optimiser is coupled with the aforementioned rotorcraft design framework. The overall methodology is deployed for the design and optimisation of a reference multipurpose Twin-Engine-Light civil rotorcraft, modelled after the Bo105 helicopter, which employs two Rolls-Royce Allison 250-C20B turboshaft engines. Through the implementation of a single-objective optimisation strategy, notionally based optimum engine design configurations are acquired in terms of engine weight, mission fuel burn and mission gaseous emissions inventory at constant technology level.The acquired optimum regenerative engine configurations are subsequently deployed for the design of conceptual rotorcraft regenerative engine configurations, targeting improved mission fuel economy, enhanced payload-range capability as well as overall environmental impact, while maintaining the respective rotorcraft airworthiness requirements. The proposed methodology essentially constitutes as an enabler for designing rotorcraft powerplants within realistic, three-dimensional operations and towards realising their associated design trade-offs at mission level.
43
Nimsiriwangso, Atip, Paul Barnes, Omid Doustdar, Miroslaw L. Wyszynski, Gasim Mohamed, Maisara Mohyeldin y Miroslaw Kowalski. "6-Stroke Engine: Thermodynamic Modelling and Design for Testing". Journal of KONES 26, n.º 2 (1 de junio de 2019): 93–106. http://dx.doi.org/10.2478/kones-2019-0037.
Texto completoResumen
Abstract In the study AVL BOOST™ is used to perform a thermodynamic simulation of a six-stroke engine, being built by a research team based in Saudi Arabia. The six-stroke cycle consists of a standard four-stroke Otto Cycle followed by a heat recovering steam expansion cycle. Water is injected into the hot combustion chamber towards the end of the Otto expansion stroke producing steam, which is used to perform work on a piston. This process produces power using waste heat and therefore increases the overall efficiency of the engine. The Robin EY28D engine, which is a single cylinder, four-stroke, gasoline engine was used for this simulation study. The engine was modelled and converted into six-stroke engine in AVL BOOST. The results show that six-stroke engine is more efficient than four-stroke engine. In six-stroke engine, the engine power is increased by 33.1% and brake specific fuel consumption (BSFC) is decreased by approximately 16%. Where emissions are concerned, Nitrogen Oxide (NOx) emission from six-stroke engine is reduced by 80%, while the Hydrocarbon (HC) emission increases by 85% compared with the original 4-stroke. Moreover, the most efficient camshaft was found and designed according to the most efficient valve profile for this engine, which is combination of 60CA° of valve duration and 10 mm of valve lifting.
44
Tvrdojevic, Mijo, Milan Vujanovic, Peter Priesching, Ferry A. Tap, Anton Starikov, Dmitry Goryntsev y Manolis Gavaises. "Implementation of the Semi Empirical Kinetic Soot Model Within Chemistry Tabulation Framework for Efficient Emissions Predictions in Diesel Engines". Open Physics 17, n.º 1 (31 de diciembre de 2019): 905–15. http://dx.doi.org/10.1515/phys-2019-0096.
Texto completoResumen
Abstract Soot prediction for diesel engines is a very important aspect of internal combustion engine emissions research, especially nowadays with very strict emission norms. Computational Fluid Dynamics (CFD) is often used in this research and optimisation of CFD models in terms of a trade-off between accuracy and computational efficiency is essential. This is especially true in the industrial environment where good predictivity is necessary for engine optimisation, but computational power is limited. To investigate soot emissions for Diesel engines, in this work CFD is coupled with chemistry tabulation framework and semi-empirical soot model. The Flamelet Generated Manifold (FGM) combustion model precomputes chemistry using detailed calculations of the 0D homogeneous reactor and then stores the species mass fractions in the table, based on six look-up variables: pressure, temperature, mixture fraction, mixture fraction variance, progress variable and progress variable variance. Data is then retrieved during online CFD simulation, enabling fast execution times while keeping the accuracy of the direct chemistry calculation. In this work, the theory behind the model is discussed as well as implementation in commercial CFD code. Also, soot modelling in the framework of tabulated chemistry is investigated: mathematical model and implementation of the kinetic soot model on the tabulation side is described, and 0D simulation results are used for verification. Then, the model is validated using real-life engine geometry under different operating conditions, where better agreement with experimental measurements is achieved, compared to the standard implementation of the kinetic soot model on the CFD side.
45
Korsunovs, Aleksandrs, Felician Campean, Gaurav Pant, Oscar Garcia-Afonso y Efe Tunc. "Evaluation of zero-dimensional stochastic reactor modelling for a Diesel engine application". International Journal of Engine Research 21, n.º 4 (29 de abril de 2019): 592–609. http://dx.doi.org/10.1177/1468087419845823.
Texto completoResumen
Prediction of engine-out emissions with high fidelity from in-cylinder combustion simulations is still a significant challenge early in the engine development process. This article contributes to this fast evolving body of knowledge by focusing on the evaluation of NO x emission prediction capability of a probability density function–based stochastic reactor engine models for a Diesel engine. The research implements a systematic approach to the study of the stochastic reactor engine model performance, underpinned by a detailed space-filling design of experiments (DoE)-based sensitivity analysis of both external and internal parameters, evaluating their effects on the accuracy in matching physical measurements of both in-cylinder conditions and NO x output. The approach proposed in this article introduces an automatic stochastic reactor engine model calibration methodology across the engine operating envelope, based on a multi-objective optimization approach. This aims to exploit opportunities for internal stochastic reactor engine model parameters tuning to achieve good overall modelling performance as a trade-off between physical in-cylinder measurements accuracy and the output NO x emission predictions error. The results from the case study provide a valuable insight into the effectiveness of the stochastic reactor engine model, showing good capability for NO x emissions prediction and trends, while pointing out the critical sensitivity to the external input parameters and modelling conditions.
46
Ra, Y., E. J. Hruby y R. D. Reitz. "Parametric study of combustion characteristics in a direct-injection diesel homogeneous charge compression ignition engine with a low-pressurefuel injector". International Journal of Engine Research 6, n.º 3 (1 de junio de 2005): 215–30. http://dx.doi.org/10.1243/146808705x7392.
Texto completoResumen
Homogeneous charge compression ignition (HCCI) combustion is an alternative to current engine combustion systems and is used as a method to reduce emissions. It has the potential nearly to eliminate engine-out NOx emissions while producing diesel-like engine efficiencies, when a premixture of gas-phase fuel and air is burned spontaneously and entirely by an autoignition process. However, when direct injection is used for diesel fuel mixture preparation in engines, the complex in-cylinder flow field and limited mixing times may result in inhomogeneity of the charge. Thus, in order to minimize non-uniformity of the charge, early injection of the fuel is desirable. However, when fuel is injected during the intake or early compression stroke, the use of high-pressure injection is limited by the relatively low in-cylinder gas pressure because of spray impingement on the cylinder walls. Thus, it is also of interest to consider low-pressure injectors as an alternative. In the present paper, the parametric behaviour of the combustion characteristics in an HCCI engine operated with a low-pressure fuel injector were investigated through numerical simulations and engine experiments. Parameters including the start-of-injection (SOI) timing and exhaust gas recirculation were considered, and diesel and n-heptane fuels were used. The results show good agreement of behaviour trends between the experiments and the numerical simulations. With its lower vaporization rates, significant effects of the SOI timing and intake gas temperature were seen for diesel fuel due to the formation of wall films. The modelling results also explained the origin of high-temperature NO x-producing regions due to the effect of the gas density on the spray.
47
Chew, J. W. y N. J. Hills. "Computational fluid dynamics and virtual aeroengine modelling". Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 223, n.º 12 (8 de septiembre de 2009): 2821–34. http://dx.doi.org/10.1243/09544062jmes1597.
Texto completoResumen
Use of large-scale computational fluid dynamics (CFD) models in aeroengine design has grown rapidly in recent years as parallel computing hardware has become available. This has reached the point where research aimed at the development of CFD-based ‘virtual engine test cells’ is underway, with considerable debate of the subject within the industrial and research communities. The present article considers and illustrates the state-of-the art and prospects for advances in this field. Limitations to CFD model accuracy, the need for aero-thermo-mechanical analysis through an engine flight cycle, coupling of numerical solutions for solid and fluid domains, and timescales for capability development are considered. While the fidelity of large-scale CFD models will remain limited by turbulence modelling and other issues for the foreseeable future, it is clear that use of multi-scale, multi-physics modelling in engine design will expand considerably. Development of user-friendly, versatile, efficient programs and systems for use in a massively parallel computing environment is considered a key issue.
48
Kamaludin, Khairul Khusairi, Aman Mohd Ihsan Mamat, Zulkifli Mohamed y Wan Saiful-Islam Wan Salim. "Water injection control modelling by using model-based calibration". IAES International Journal of Robotics and Automation (IJRA) 11, n.º 4 (1 de diciembre de 2022): 304. http://dx.doi.org/10.11591/ijra.v11i4.pp304-314.
Texto completoResumen
<p><span lang="EN-US">This study presents the development of water injection system for turbocharged spark ignition engine. The water injection control system is built for turbocharged spark ignition (SI) engine where water was injected at the intake port just before the throttle body. The data was collected from the simulation through the GT-Power software to determine the optimized injection output for the engine. Single-stage statistical engine responses and boundary models were established by using Model-Based Calibration Toolbox. Control system was built using Simulink and simulation tests were conducted based on the speed and throttle position as the variables. The highest value of brake torque achieved in the GT-Power simulation was taken as the base value to determine the injection amount. The mean value of the predicted injection was recorded at 12.29 g/s while the variance of the predicted injection to the optimized injection was below 1%. The control system was simulated with the set predicted injection and the standard deviation of the predicted injection was 1.18. The control system simulation recorded a low percentage of 0.04% variance to the optimized injection with the pulse width modulation signal. The control system is ideal to be constructed and tested on actual engine test bed.</span></p>
49
Ling, C. H. y M. A. Abas. "One-Dimensional Simulation Using Port Water Injection for a Spark Ignition Engine". International Journal of Automotive and Mechanical Engineering 15, n.º 4 (24 de diciembre de 2018): 5803–14. http://dx.doi.org/10.15282/ijame.15.4.2018.7.0444.
Texto completoResumen
Water injection is a promising solution to reduce fuel consumption while improving the performance of a turbocharged gasoline engine. One-dimensional (1D) engine simulation software, AVL BOOST is rarely used to model water injection. Therefore, this study is aimed to demonstrate the detailed port water injection modelling via AVL BOOST. A four-cylinder turbocharged gasoline engine was developed in AVL BOOST based on the specification of the engine test rig and verified to be used as the baseline model. The port water injection modelling was then added to the baseline model. Water to fuel mass ratios of 0.05, 0.10, 0.15, 0.2 and 0.25 were chosen as the variables to investigate the effect of water injection on the engine performance. The results showed that maximum engine torque and IMEP increased by 10.80% and 8.65%, respectively at 3000 rpm. The water injection also reduced the in-cylinder pressure at the end of the compression stroke, reducing the compression work and improving efficiency. The reduction of combustion temperature also indicates potential for NOx reduction. The lower exhaust temperature can reduce the use of fuel enrichment which consequently reduces the fuel consumption. Conclusively, the water injection model can predict the engine performance parameters accurately.
50
Righi, Mauro, Vassilios Pachidis, László Könözsy, Fanzhou Zhao y Mehdi Vahdati. "Three-dimensional low-order surge model for high-speed axial compressors". Journal of the Global Power and Propulsion Society 4 (18 de diciembre de 2020): 274–84. http://dx.doi.org/10.33737/jgpps/130790.
Texto completoResumen
Surge in modern aero-engines can lead to violent disruption of the flow, damage to the blade structures and eventually engine shutdown. Knowledge of unsteady performance and loading during surge is crucial for compressor design, however, the understanding and prediction capability for this phenomenon is still very limited. While useful for the investigation of specific cases, costly experimental tests and high-fidelity CFD simulations cannot be used routinely in the design process of compressor systems. There is therefore an interest in developing a low-order model which can predict compressor performance during surge with sufficient accuracy at significantly reduced computational cost. This paper describes the validation of an unsteady 3D through-flow code developed at Cranfield University for the low-order modelling of surge in axial compressors. The geometry investigated is an 8-stage rig representative of a modern aero-engine IP compressor. Two deep surge events are modelled at part speed and full speed respectively. The results are compared against high-fidelity, full annulus, URANS simulations conducted at Imperial College. Comparison of massflow, pressure and temperature time histories shows a close match between the low-order and the higher-fidelity methods. The low-order model is shown capable of predicting many transient flow features which were observed in the high-fidelity simulations, while reducing the computational cost by up to two orders of magnitude.