Letteratura scientifica selezionata sul tema "Engine look-up tables"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Consulta la lista di attuali articoli, libri, tesi, atti di convegni e altre fonti scientifiche attinenti al tema "Engine look-up tables".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Articoli di riviste sul tema "Engine look-up tables":
1
Stotsky, A. A. "Data-driven algorithms for engine friction estimation". Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 221, n. 7 (1 luglio 2007): 901–9. http://dx.doi.org/10.1243/09544070jauto230.
Abstract (sommario):
Errors in the estimation of friction torque in modern spark ignition automotive engines necessitate the development of real-time algorithms for adaptation of the friction torque. Friction torque in the engine control unit is presented as a look-up table with two input variables (the engine speed and indicated engine torque). The algorithms proposed in this paper estimate the engine friction torque via the crankshaft speed fluctuations at the fuel cut-off state and at idle. A computationally efficient filtering algorithm for reconstruction of the first harmonic of a periodic signal is used to recover an amplitude which corresponds to engine events from the noise-contaminated engine speed measurements at the fuel cut-off state. The values of the friction torque at the nodes of the look-up table are updated, when new measured data of the friction torque are available. New data-driven algorithms which are based on a stepwise regression method are developed for adaptation of look-up tables. The algorithms are verified by using a spark ignition six-cylinder prototype engine.
2
Bastian, Andreas. "Modeling Fuel Injection Control Maps Using Fuzzy Logic and Neural Networks". Journal of Robotics and Mechatronics 6, n. 4 (20 agosto 1994): 340–44. http://dx.doi.org/10.20965/jrm.1994.p0340.
Abstract (sommario):
Determining the correct ignition point of the air-fuel mixture is critical in order to achieve maximum output torque and to reduce exhaust emissions. In some fuel injection control systems the amount of air cannot be detected, thus, look-up tables are utilized, which contain the amount of air for given engine speed and inlet manifold pressure. In this paper, we model the look-up table using fuzzy logic. A neural network approach is used to identify the inputs of the fuzzy model.
3
Hausberg, F., M. Plöchl, M. Rupp, P. Pfeffer e S. Hecker. "Combination of map-based and adaptive feedforward control algorithms for active engine mounts". Journal of Vibration and Control 23, n. 19 (20 gennaio 2016): 3092–107. http://dx.doi.org/10.1177/1077546315626323.
Abstract (sommario):
Active engine mounts significantly contribute to ensure the comfort in vehicles with emission-reducing engine technologies, e.g., cylinder-on-demand (COD), downsizing or turbochargers. To control active engine mounts, either adaptive or non-adaptive feedforward control is commonly employed. Since both approaches have previously been treated separately, this study proposes methods to connect them in terms of multiple-input-multiple-output Newton/FxLMS adaptive filters with self-trained, grid-based look-up tables. The look-up tables are incorporated as parameter-maps or parallel-maps, respectively. By combining the two feedforward control strategies, their inherent advantages, i.e., the adaptivity of adaptive filtering and the direct impact as well as the tracking behavior of map-based feedforward control, are utilized. The proposed control structures are illustrated by simulation and experimentally demonstrated in a vehicle with a V8-COD engine. While both methods significantly reduce the convergence time of the adaptive filter, the parallel implementation additionally improves the tracking behavior during fast engine run-ups.
4
Vogt, Michael, Norbert Mu¨ller e Rolf Isermann. "On-Line Adaptation of Grid-Based Look-up Tables Using a Fast Linear Regression Technique". Journal of Dynamic Systems, Measurement, and Control 126, n. 4 (1 dicembre 2004): 732–39. http://dx.doi.org/10.1115/1.1849241.
Abstract (sommario):
Advanced control systems require accurate process models, while processes are often both nonlinear and time variant. After introducing the identification of nonlinear processes with grid-based look-up tables, a new learning algorithm for on-line adaptation of look-up tables is proposed. Using a linear regression approach, this new adaptation algorithm considerably reduces the convergence time in relation to conventional gradient-based adaptation algorithms. An application example and experimental results are shown for the learning feedforward control of the ignition angle of a spark ignition engine.
5
Puleston, P. F., G. Monsees e S. K. Spurgeon. "Air-fuel ratio and speed control for low emission vehicles based on sliding mode techniques". Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 216, n. 2 (1 marzo 2002): 117–24. http://dx.doi.org/10.1243/0959651021541480.
Abstract (sommario):
This paper deals with the combined air-fuel ratio (AFR) and speed control of automotive engines. The robust controller is developed using dynamic sliding mode (SM) control design methods. The proposed controller set-up is tested under realistic operating conditions by means of computer simulation using a comprehensive non-linear model of a four-stroke engine, specifically provided by the automotive industry for these purposes. This accurate industrial model comprises extensive dynamics description and numerous look-up tables representing parameter characteristics obtained from experimental data. The SM controller set-up proves to be robust to model uncertainties and unknown disturbances, regulating effectively the engine speed for a wide range of set-points while maintaining the AFR at the stoichiometric value.
6
Dilibe, Ifeanyi. "Computational model of the fuel consumption and exhaust temperature of a heavy duty diesel engine using MATLAB/SIMULINK". Poljoprivredna tehnika 45, n. 4 (2020): 51–70. http://dx.doi.org/10.5937/poljteh2004051d.
Abstract (sommario):
A model of a diesel engine and its electronic control system was developed to investigate the engine behaviour in a vehicle simulation environment. The modelled quantities were brake torque, fuel consumption and exhaust gas temperature and were based on engine speed and pedal position. In order to describe these outputs the inlet air flow and boost pressure were also modelled and used as inner variables. The model was intended to be implemented on board a vehicle in a control unit which had limited computational performance. To keep the model as computationally efficient as possible the model basically consists of look-up tables and polynomials. First order systems were used to describe the dynamics of air flow and exhaust temperature. The outputs enable gear shift optimization over three variables, torque for vehicle acceleration, fuel consumption for efficiency and exhaust temperature to maintain high efficiency in the exhaust after treatment system. The engine model captures the low frequent dynamics of the modelled quantities in the closed loop of the engine and its electronic control system. The model only consists of three states, one for the pressure build up in the intake manifold and two states for modelling the exhaust temperature. The model was compared to measured data from an engine test cell (as got in INNOSON NIG. LTD.) and the mean absolute relative error were lower than 6.8%, 7.8% and 5.8% for brake torque, fuel consumption and exhaust gas temperature respectively. These results were considered good given the simplicity of the model.
7
Zhang, Haibo, e Fengyong Sun. "Direct Surge Margin Control for Aeroengines Based on Improved SVR Machine and LQR Method". Mathematical Problems in Engineering 2013 (2013): 1–17. http://dx.doi.org/10.1155/2013/870215.
Abstract (sommario):
A novel scheme of high stability engine control (HISTEC) on the basis of an improved linear quadratic regulator (ILQR), called direct surge margin control, is derived for super-maneuver flights. Direct surge margin control, which is different from conventional control scheme, puts surge margin into the engine closed-loop system and takes surge margin as controlled variable directly. In this way, direct surge margin control can exploit potential performance of engine more effectively with a decrease of engine stability margin which usually happened in super-maneuver flights. For conquering the difficulty that aeroengine surge margin is undetectable, an approach based on improved support vector regression (SVR) machine is proposed to construct a surge margin prediction model. The surge margin modeling contains two parts: a baseline model under no inlet distortion states and the calculation for surge margin loss under supermaneuvering flight conditions. The previous one is developed using neural network method, the inputs of which are selected by a weighted feature selection algorithm. Considering the hysteresis between pilot input and angle of attack output, an online scrolling window least square support vector regression (LSSVR) method is employed to firstly estimate inlet distortion index and further compute surge margin loss via some empirical look-up tables.
8
Zhang, Y., X. Chen, X. Zhang, H. Jiang e W. Tobler. "Dynamic Modeling and Simulation of a Dual-Clutch Automated Lay-Shaft Transmission". Journal of Mechanical Design 127, n. 2 (1 marzo 2005): 302–7. http://dx.doi.org/10.1115/1.1829069.
Abstract (sommario):
This paper presents a systematic model for the simulation and analysis of a power-shift transmission that features a dual-clutch design. The paper models the kinematics, dynamics, and control of the transmission for the analysis of powertrain overall performance and shift transient characteristics. The model is implemented in an object-oriented software tool. Analytical formulations and look-up tables are both used for modeling of powertrain components. The vehicle system model is established by integrating the various components and subsystem models according to the transmission power flow and control logic. The input to the simulation model is the vehicle speed-time profile and the output provides the speed follow-up, engine, and clutch operation status for the drive range and shift processes involved. As a numerical example, the model is used for a vehicle equipped with the power-shift transmission to simulate the speed follow-up over a specified drive range and the dynamic transients during shifts.© 2004 American Institute of Physics.
9
Marinoni, Andrea Massimo, Angelo Onorati, Giacomo Manca Di Villahermosa e Simon Langridge. "Real Driving Cycle Simulation of a Hybrid Bus by Means of a Co-Simulation Tool for the Prediction of Performance and Emissions". Energies 16, n. 12 (15 giugno 2023): 4736. http://dx.doi.org/10.3390/en16124736.
Abstract (sommario):
This work is focused on the simulation of a complete hybrid bus vehicle model performing a real-world driving cycle. The simulation framework consists of a coupled co-simulation environment, where all the vehicle sub-system models are linked to achieve a real time exchange of input and output signals. In the vehicle model also the electric devices of the powertrain and accumulation system are included. This co-simulation platform is applied to investigate the hybridization of a 12-m city bus, performing a typical urban driving mission. A comparison between the conventional powertrain is performed against the hybridized version, to highlight the advantages and challenges. In particular, the novelty of this modeling approach is that the IC engine simulation does not rely on pre-processed look-up tables, but exploits a high-fidelity one-dimensional thermo-fluid dynamic model. However, it was necessary to develop a fast simulation methodology to exploit this predictive tool, achieving a low computational cost. The 1D engine model is first validated against the experimental engine map data available, showing a good model predictivity. Then the 1D engine model and the other models of the powertrain are coupled to the vehicle model, in order to follow the prescribed velocity profile of the driving cycle. The complete model is applied under different conditions, to evaluate the impact on performance and emissions and assess the simulation predictivity.
10
Dowell, Peter G., Sam Akehurst e Richard D. Burke. "Characterisation and optimisation of a real-time diesel engine model". Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 231, n. 14 (1 febbraio 2017): 1913–34. http://dx.doi.org/10.1177/0954407017691618.
Abstract (sommario):
Accurate real-time engine models are an essential step to allow the development of control algorithms in parallel to the development of engine hardware using hardware-in-the-loop applications. A physics-based model of the engine high-pressure air path and combustion chamber is presented. The model was parameterised using data from a small set of carefully selected operating conditions for a 2.0 l diesel engine. The model was subsequently validated over the complete engine operating map with exhaust gas recirculation and without exhaust gas recirculation. A high level of fit was achieved with R2 values above 0.94 for the mean effective pressure and above 0.99 for the air flow rate. The model run time was then reduced for real-time application by using forward differencing and single-precision floating-point numbers and by calculating the in-cylinder prediction for only a single cylinder. A further improvement of 25% in the run time was achieved by improving the submodels, including the strategic use of one-dimensional and two-dimensional look-up tables with optimised resolution. The model exceeds the performance of similar models in the literature, achieving a crank angle resolution of 0.5° at 4000 r/min. This simulation step size still yields good accuracy in comparison with a crank angle resolution of 0.1° and was validated against the experimental results from a New European Driving Cycle. The real-time model allows the development of control strategies before the engine hardware is available, meaning that more time can be spent to ensure that the engine can meet the performance and the emissions requirements over its full operating range.
Tesi sul tema "Engine look-up tables":
1
Blanco, Rodríguez David. "Modelling and observation of exhaust gas concentrations for diesel engine control". Doctoral thesis, Universitat Politècnica de València, 2013. http://hdl.handle.net/10251/32666.
Abstract (sommario):
La Tesis Doctoral estudia la observaci'on en tiempo real de la concentraci'on en el colector de escape de 'oxidos de nitr'ogeno (NOx) y del dosado en motores
diesel sobrealimentados (¿
'1
). Para ello se combinan dos fuentes de informaci'on diferentes:
¿ Sensores capaces de proporcionar una media de dichas variables,
¿ y modelos orientados a control que estiman estas variables a partir de otras
medidas del motor.
El trabajo parte de la evaluaci'on de la precisi'on de los sensores, realizada mediante la comparaci'on de su medida con la proporcionada por equipos anal'¿ticos de
alta precisi'on, que son usados como est'andares de calibraci'on est'atica. Tambi'en se
desarrollan en la Tesis m'etodos para la calibraci'on de la din'amica del sensor; dichos m'etodos permiten identi¿car un modelo de comportamiento del sensor y revelar
su velocidad de respuesta. En general, estos sensores demuestran ser precisos pero
relativamente lentos.
Por otra parte, se proponen modelos r'apidos para la estimaci'on de NOx y ¿
'1
.
Estos m'etodos, basados en relaciones f'¿sicas, tablas de par'ametros y una serie de
correcciones, emplean las medidas proporcionadas por otros sensores con el ¿n de
proporcionar una estimaci'on de las variables de inter'es. Los modelos permiten una
estimaci'on muy r'apida, pero resultan afectados por efectos de deriva que comprometen
su precisi'on.
Con el ¿n de aprovechar las caracter'¿sticas din'amicas del modelo y mantener
la precisi'on en estado estacionario del sensor, se proponen t'ecnicas de fusi'on de la
informaci'on basadas en la aplicaci'on de ¿ltros de Kalman (KF). En primer lugar, se
dise¿na un KF capaz de combinar ambas fuentes de informaci'on y corregir en tiempo
real el sesgo entre las dos se¿nales. Posteriormente, se estudia la adaptaci'on en tiempo
real de los par'ametros del modelo con el ¿n de corregir de forma autom'atica los
problemas de deriva asociados al uso de modelos.
Todos los m'etodos y procedimientos desarrollados a lo largo de la presente Tesis
Doctoral se han aplicado de forma experimental a la estimaci'on de NOx y ¿
'1
. De
forma adicional, la Tesis Doctoral desarrolla aspectos relativos a la transferencia de
estos m'etodos a los motores de serie.The dissertation covers the problem of the online estimation of diesel engine exhaust concentrations of NOx and '1. Two information sources are utilised: ¿ on-board sensors for measuring NOx and '1, and ¿ control oriented models (COM) in order to predict NOx and '1. The evaluation of the static accuracy of these sensors is made by comparing the outputs with a gas analyser, while the dynamics are identified on-board by perform- ing step-like transitions on NOx and '1 after modifying ECU actuation variables. Different methods for identifying the dynamic output of the sensors are developed in this work; these methods allow to identify the time response and delay of the sensors if a sufficient data set is available. In general, these sensors are accurate but present slow responses. Afterwards, control oriented models for estimating NOx and '1 are proposed. Regarding '1 prediction, the computation is based on the relative fuel-to-air ratio, where fuel comes from an ECU model and air mass flow is measured by a sensor. For the case of NOx, a set-point relative model based on look-up tables is fitted for representing nominal engine emissions with an exponential correction based on the intake oxygen variation. Different corrections factor for modeling other effects such as the thermal loading of the engine are also proposed. The model is able to predict NOx fast with a low error and a simple structure. Despite of using models or sensors, model drift and sensor dynamic deficiencies affect the final estimation. In order to solve these problems, data fusion strategies are proposed by combining the steady-state accuracy of the sensor and the fast estimation of the models by means of applying Kalman filters (KF). In a first approach, a drift correction model tracks the bias between the model and the sensor but keeping the fast response of the model. In a second approach, the updating of look-up tables by using observers is coped with different versions based on the extended Kalman filter (EKF). Particularly, a simplified KF allows to observe the parameters with a low computational effort. Finally, the methods and algorithms developed in this work are combined and applied to the estimation of NOx and '1. Additionally, the dissertation covers aspects relative to the implementation of the methods in series engines.
Blanco Rodríguez, D. (2013). Modelling and observation of exhaust gas concentrations for diesel engine control [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/32666
TESIS
Premiado
2
Hambarek, Djamel Eddine. "Développement d'une méthodologie d'essais dynamiques appliquée à la mise au point moteur". Electronic Thesis or Diss., Ecole centrale de Nantes, 2023. http://www.theses.fr/2023ECDN0035.
Abstract (sommario):
Les travaux de cette thèse de doctorat s’inscrivent dans le contexte d’évolution desnormes de dépollution des moteurs thermiquescouplée aux exigences de baisse de la consommation des véhicules. La méthodologie développée tente de répondre avec un processus industriel efficace aux exigences d’émissions en roulage réel, dites RDE (Real Driving Emissions). La méthode proposée est basée sur la technique des plans d’expériences dynamiques utilisant les suites à faible discrépance : les résultats d’essais sont utilisés afin d’entraîner un modèle de réseau de neurones type LSTM capable de prédire l’historique des sorties (les masses de polluants CO, HC, NOx) pour chaque combinaison donnée en entrée. Le modèle est utilisé ensuite pour nourrir une boucle d’optimisation basée sur un algorithme génétique afin de mettre au point les cartographies moteur optimales.Les travaux se focalisent sur la phase de mise en action du moteur, qui est comprise entre l’instant de démarrage et l’instant où le système de post-traitement est amorcé, c’est-à-dire lorsque le catalyseur a atteint la température lui permettant d’être efficace. Cette phase est capitale car elle concentre l’essentiel des émissions lors d’un cycle d’homologation : la mise en action doit donc sans cesse être optimisée pour répondre aux nouvelles contraintes réglementaires. Elle constitue donc un champ d’application de la méthodologie à la fois cohérent et pertinent. Les résultats montrent des améliorations notables concernant les CO, HC et Nox en comparaison de la méthode classique (essais en régime permanent)The work of this thesis responds to the context of the evolution of engine depollution norms together with the increase of the clientrequirements. It proposes a complete methodology of engine calibration considering dynamic effects with the aim of an efficient control in terms of emissions and performances. The method is divided into four steps: the dynamic design of experiments generating a set of RDE (Real Driving Emissions) cycles and dynamic variations of engine parameters using low discrepancy sequences: test results are used to train a dynamical model using LSTM neural network to predict output dynamic variations(CO, HC, NOx, Exhaust flow and temperature). The trained model is used in an optimization loop to calibrate the engine parameters using a genetic algorithm. The catalyst warm-up phase is the chosen phase for the development of the method. It is the phase occuring from engine start until the catalyst is the most efficient. It is indeed the phase with the most important emissions which is coherent with the aim of the engine calibration. The results showed noticeable improvements of CO, HC and Nox reduction compared to the steady state (baseline) method
Capitoli di libri sul tema "Engine look-up tables":
1
Bentley, Peter J. "Introduction". In Digitized. Oxford University Press, 2012. http://dx.doi.org/10.1093/oso/9780199693795.003.0005.
Abstract (sommario):
They obey our instructions with unlimited patience. They store the world’s knowledge and make it accessible in a split second. They are the backbone of modern society. Yet they are largely ignored. Computers. They comprise our crowning achievements to date, the pinnacle of all tools. Computer processors and software represent the most complex designs humans have ever created. The science of computers has enabled one of the most extraordinary transformations of our societies in human history. . . . You switch on your computer and launch the Internet browser. A one-word search for ‘pizza’ finds a list of pizza restaurants in your area. One click with the mouse and you are typing in your address to see if this restaurant delivers. They do! And they also allow you to order online. You choose the type of pizza you feel like, adding your favourite toppings. The restaurant even allows you to pay online, so you type in your credit card number, your address, and the time you’d like the delivery. You choose ‘as soon as possible’ and click ‘pay’. Just thirty-five minutes later there is a knock on your door. The pizza is here, smelling delicious. You tip the delivery guy and take the pizza to your table to eat. Ordering pizza is nothing unusual for many of us around the world. Although it may seem surprising, this increasingly common scenario with cheap prices, fast delivery, and access to such variety of food for millions of customers is only possible because of computers. In the situation above you might have spotted just one computer. If we take a look behind the scenes, the number of computers involved in bringing your pizza is astonishing. When you switched on your computer, you actually powered up many computers that all work together to make the display, mouse, keyboard, broadband, and main computer operate. Your computer linked itself to the Internet—which is a worldwide network of computers— with the help of computers of the phone company and Internet service provider. When you searched for ‘pizza’ the request was routed between several computers before reaching the search engine computers.
Atti di convegni sul tema "Engine look-up tables":
1
Serrano, José Ramón, Francisco José Arnau, Luis Miguel García-Cuevas González, Alejandro Gómez-Vilanova e Stephane Guilain. "Impact of a Holistic Turbocharger Model in the Prediction of Engines Performance in Transient Operation and in Steady State With LP-EGR". In ASME 2018 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/icef2018-9550.
Abstract (sommario):
Turbocharged engines are the standard powertrain type of internal combustion engines for both spark ignition and compression ignition concepts. Turbochargers modeling traditionally rely in look up tables based on turbocharger manufacturer provided maps. These maps as the only secure source of information. They are used both for the matching between reciprocating engine and the turbocharger and for the further engine optimization and performance analysis. In the last years have become evident that only these maps are not being useful for detailed calculation of variables like after-treatment inlet temperature (turbine outlet), intercooler inlet temperature (compressor outlet) and engine BSFC at low loads. This paper shows a comprehensive study that quantifies the errors of using just look up tables compared with a model that accounts for friction losses, heat transfer and gas-dynamics in a turbocharger and in a conjugated way. The study is based in an Euro 5 engine operating in load transient conditions and using a LP-EGR circuit during steady state operation.
2
Tap, Ferry, Casper Meijer, Dmitry Goryntsev, Anton Starikov, Mijo Tvrdojevic e Peter Priesching. "Predictive CFD Modeling of Diesel Engine Combustion Using an Efficient Workflow Based on Tabulated Chemistry". In ASME 2018 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/icef2018-9758.
Abstract (sommario):
The use of 3D CFD combustion models based on tabulated chemistry is becoming increasingly popular. Especially the runtime benefit is attractive, as the tabulated chemistry method allows to include state-of-the-art chemical reaction schemes in CFD simulations. In this work, the Tabkin FGM combustion model in AVL FIRE™ is used to assess the predictivity on a large database of a light-duty Diesel engine measurements. The AVL TABKIN™ software is used to create the chemistry look-up tables for the Tabkin FGM model. The TABKIN software has been extended with the kinetic soot model, where the soot mass fraction calculation is done during the chemistry tabulation process, as well as an NO model using a second progress variable. From recent validation studies, a best-practice and nearly automated workflow has been derived to create the look-up tables for Diesel engine applications based on minimal input. This automated modeling workflow is assessed in the present study. A wide range of parameter variations are investigated for 5 engine load points, with and without EGR, in total 186 cases. This large number of CFD simulations is run in an automated way and the parameters of the CFD sub-models are kept equal as well as all numerical settings. Results are presented for combustion and emissions (NO and soot). Combustion parameters and NO emissions correlate very well to the experimental database with R2 values above 0.95. Soot predictions give order-of-magnitude agreement for most of the cases; the trend however is not always respected, which limits the overall correlation for all cases together, as reported by other authors. Further fundamental research on modeling soot formation and oxidation process remains required to improve the models. In terms of CPU time, the present study was executed on an off-the-shelf HPC cluster, using 8 CPU cores per case and requiring around 3 hrs of wall-time per case, e.g. such a large set of calculations can be simulated overnight on a standard HPC cluster.
3
Siddareddy, Reddy Babu, Tim Franken, Michal Pasternak, Larisa Leon de Syniawa, Johannes Oder, Hermann Rottengruber e Fabian Mauss. "Real-Time Simulation of CNG Engine and After-Treatment System Cold Start. Part 1: Transient Engine-Out Emission Prediction Using a Stochastic Reactor Model". In WCX SAE World Congress Experience. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2023. http://dx.doi.org/10.4271/2023-01-0183.
Abstract (sommario):
<div class="section abstract"><div class="htmlview paragraph">During cold start of natural gas engines, increased methane and formaldehyde emissions can be released due to flame quenching on cold cylinder walls, misfiring and the catalyst not being fully active at low temperatures. Euro 6 legislation does not regulate methane and formaldehyde emissions. New limits for these two pollutants have been proposed by CLOVE consortium for Euro 7 scenarios. These proposals indicate tougher requirements for aftertreatment systems of natural gas engines.</div><div class="htmlview paragraph">In the present study, a zero-dimensional model for real-time engine-out emission prediction for transient engine cold start is presented. The model incorporates the stochastic reactor model for spark ignition engines and tabulated chemistry. The tabulated chemistry approach allows to account for the physical and chemical properties of natural gas fuels in detail by using a-priori generated laminar flame speed and combustion chemistry look-up tables. The turbulence-chemistry interaction within the combustion chamber is predicted using a K-k turbulence model. The optimum turbulence model parameters are trained by matching the experimental cylinder pressure and engine-out emissions of nine steady-state operating points.</div><div class="htmlview paragraph">Subsequently, the trained engine model is applied for predicting engine-out emissions of a WLTP passenger car engine cold start. The predicted engine-out emissions comprise nitrogen oxide, carbon monoxide, carbon dioxide, unburnt methane, formaldehyde, and hydrogen. The simulation results are validated by comparing to transient engine measurements at different ambient temperatures (-7°C, 0°C, 8°C and 20°C). Additionally, the sensitivity of engine-out emissions towards air-fuel-ratio (λ=1.0 and λ=1.3) and natural gas quality (H-Gas and L-Gas) is investigated.</div></div>
4
Stricker, Karla, Lyle Kocher, Ed Koeberlein, D. G. Van Alstine e Greg Shaver. "Turbocharger Map Reduction for Control-Oriented Modeling". In ASME 2011 Dynamic Systems and Control Conference and Bath/ASME Symposium on Fluid Power and Motion Control. ASMEDC, 2011. http://dx.doi.org/10.1115/dscc2011-5992.
Abstract (sommario):
The gas exchange process in a modern diesel engine is generally modeled using manufacturer-provided performance maps that describe mass flows through, and efficiencies of, the turbine and compressor. These maps are typically implemented as look-up tables requiring multiple interpolations based on pressure ratios across the turbine and compressor, as well as the turbocharger shaft speed. In the case of variable-geometry turbochargers, the nozzle position is also an input to these maps. This method of interpolating or extrapolating data is undesirable when modeling for estimation and control, and though there have been several previous efforts to reduce dependence on turbomachinery maps, many of these approaches are complex and not easily implemented in engine control systems. As such, the aim of this paper is to reduce turbocharger maps to analytical functions for models amenable to estimation and control.
5
Kong, Changduk, Youngju Koo, Seonghee Kho e Hyeok Ryu. "Study on a GUI Type Fault Diagnostic Program for a Turboshaft Engine Using Fuzzy and Neural Networks". In ASME Turbo Expo 2010: Power for Land, Sea, and Air. ASMEDC, 2010. http://dx.doi.org/10.1115/gt2010-22537.
Abstract (sommario):
The helicopter to be operated in a severe flight environmental condition must have a very reliable propulsion system. On-line condition monitoring and fault detection of the engine can promote reliability and availability of the helicopter propulsion system. A hybrid health monitoring program using Fuzzy Logic and Neural Network Algorithms is can proposed. In this hybrid method, the Fuzzy Logic identify easily the faulted components from engine measuring parameter changes, and the Neural Networks can quantify accurately its identified faults. In order to use effectively the fault diagnostic system, a GUI (Graphical User Interface) type program is newly proposed. This program is composed of the real time monitoring part, the engine condition monitoring part and the fault diagnostic part. The real time monitoring part can display measuring parameters of the study turboshaft engine such as power turbine inlet temperature, exhaust gas temperature, fuel flow, torque and gas generator speed. The engine condition monitoring part can evaluate the engine condition through comparison between monitoring performance parameters the base performance parameters analyzed by the base performance analysis program using look-up tables. The fault diagnostic part can identify and quantify the single faults the multiple faults from the monitoring parameters using hybrid method.
6
Rencher, J. K., A. H. Massoudi e D. W. Guillaume. "CFD Analysis of the Combustion of Hydrogen in a Simulated Two Dimensional Scramjet Engine". In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-61326.
Abstract (sommario):
The purpose of this research is to accurately simulate combustion in a scramjet engine using a CFD (Computational Fluid Dynamics) software package called Fluent and to validate the results with existing experimental data from NASA Langley Research Center[1]. The use of a particular engine characteristic called compression ramp injection was used to increase the mixing of air and fuel inside the combustion duct as well as provide the necessary compression of the fuel/air mixture. The duct length and other pertinent dimensions were also determined by published data from NASA [1]. The engine model used is relatively small and, at this stage, can be thought of as a two dimensional combustor duct rather than a true engine. The scope of this project involves the simultaneous calculations and analysis of both combustion and high-speed compressible flow. Thermodynamic data was used to create hydrogen fuel in a Fluent module called prePDF (probability density function), which calculates the look-up tables and chemical reactions for the fuel. Non-premixed combustion at Mach 2 was carried out using various equivalence ratios, (ratio of actual fuel/air mixture to stoichiometric fuel/air mixture) ranging from .4 to 1.4. The basic characteristics of the numerical model are as follows: steady state; non-premixed combustion; hydrogen fuel PDF model with 4 species; k-epsilon viscous model. Results of the numerical analysis include a comparison of combustion efficiencies for various equivalence ratios to the combustion efficiencies and equivalence ratios obtained by NASA in their experimental ground test facility at Langley Research Center [1].
7
Marion, Flore, Fred Betz e David Archer. "Cogeneration System Modeling Based on Experimental Results". In ASME 2010 4th International Conference on Energy Sustainability. ASMEDC, 2010. http://dx.doi.org/10.1115/es2010-90184.
Abstract (sommario):
A 25 kWe cogeneration system has been installed by the School of Architecture of Carnegie Mellon University that provides steam and hot water to its Intelligent Workplace, the IW. This cogeneration system comprises a biodiesel fueled engine generator, a steam generator that operates on its exhaust, a hot water heat exchanger that operates on its engine coolant, and a steam driven absorption chiller. The steam and hot water are thus used for cooling, heating, and ventilation air dehumidification in the IW. This cogeneration system is a primary component of an overall energy supply system that halves the consumption of primary energy required to operate the IW. This cogeneration system was completed in September 2007, and extensive tests have been carried out on its performance over a broad range of power and heat outputs with Diesel and biodiesel fuels. In parallel, a detailed systems performance model of the engine generator, its heat recovery exchangers, the steam driven absorption chiller, a ventilation and air dehumidification unit, and multiple fan coil cooling/heating units has been programmed making use of TRNSYS to evaluate the utilization of the heat from the unit in the IW. In this model the distribution of heat from the engine to the exhaust, to the coolant, and directly to the surroundings has been based on an ASHRAE model. While a computational model was created, its complexity made calculation of annual performance excessively time consuming and a simplified model based on experimental data was created. The testing of the cogeneration system at 6, 12, 18 and 25 kWe is now completed and a wealth of data on flow rates, temperatures, pressures throughout the system were collected. These data have been organized in look up tables to create a simplified empirical TRNSYS component for the cogeneration system in order to allow representative evaluation of annual performance of the system for three different mode of operation. Using the look up table, a simple TRNSYS module for the cogeneration system was developed that equates fuel flow to electricity generation, hot water generation via the coolant heat exchanger, and steam production via the steam generator. The different modes of operation for this cogeneration system can be design load: 25 kWe, following the thermal — heating or cooling — load, following the ventilation regeneration load. The calculated annual efficiency for the different mode is respectively 66% 68% and 65%. This cogeneration installation was sized to provide guidance on future cogeneration plant design for small commercial buildings. The new cogeneration TRNSYS component has been created to be applicable in the design of various buildings where a similar cogeneration system could be implemented. It will assist in selection of equipment and of operating conditions to realize an efficient and economic cogeneration system.
8
Majoumerd, Mohammad Mansouri, Peter Breuhaus, Jure Smrekar, Mohsen Assadi, Carmine Basilicata, Stefano Mazzoni, Leila Chennaoui e Giovanni Cerri. "Impact of Fuel Flexibility Needs on a Selected GT Performance in IGCC Application". In ASME Turbo Expo 2012: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/gt2012-68862.
Abstract (sommario):
As part of a European Union (EU) funded H2-IGCC project, a baseline IGCC power plant was established; this was presented at the ASME Turbo Expo 2011 (GT2011-45701). The current paper focuses on a detailed investigation of the impact of using various fuels considering different operating conditions on the gas turbine performance, and the identification of technical solutions for the realization of the targeted fuel flexibility. Using a lumped model, based on real engine data, compressor and turbine maps of the targeted engine were generated and implemented into the detailed GT model made in the commercial heat and mass balance program, IPSEpro. The implementation was done in terms of look-up tables. The impact of fuel change on the gas turbine island has been investigated and reported in this paper. Calculation results show that for the given boundary conditions, the surge margin of the compressor was slightly reduced when natural gas was replaced by hydrogen-rich syngas. The use of cleaned syngas instead of hydrogen-rich syngas resulted in a considerable reduction of the surge margin and elevation of the turbine outlet temperature (TOT) at design point conditions, when keeping the turbine inlet temperature (TIT) and compressor inlet mass flow unchanged. To maintain the TOT and improve the surge margin, when operating the engine with cleaned syngas, a combination of adjustment of variable inlet guide vanes (VIGV) and reduced TIT was considered. A parameter study was carried out to provide better understanding of the current limitations of the engine and to identify possible modifications to improve fuel flexibility.
9
Elmagdoub, Abdelrahman W. M., Urban Carlson, Mattias Halmearo, James Turner, Chris Brace, Sam Akehurst e Nic Zhang. "Freevalve: Control and Optimization of Fully Variable Valvetrain-Enabled Combustion Strategies for Steady-State Part Load Performance and Transient Rise Times". In WCX SAE World Congress Experience. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2023. http://dx.doi.org/10.4271/2023-01-0294.
Abstract (sommario):
<div class="section abstract"><div class="htmlview paragraph">In passenger car development, extreme ICE downsizing trends have been observed over the past decade. While this comes with fuel economy benefits, they are often obtained at the expense of Brake Mean Effective Pressure (BMEP) rise time in transient engine response. Through advanced control strategies, the use of Fully Variable Valvetrain (FVVT) technologies has the potential to completely mitigate the associated drivability-penalizing constraints. Adopting a statistical approach, key part load performance engine parameters are analyzed. Design-of-Experiment data is generated using a validated GT-Power model for a Freevalve-converted turbocharged Ultraboost engine. Subsequently, MathWorks' Model Based Calibration (MBC) toolbox is utilized to interpret the data through model fitments using neural network models of optimized architectures. Calibration Generation (CAGE) toolbox is ultimately used to identify best-case look-up tables for the part load steady state performance points based on concluded, case specific, BSFC values. Transient tip-in events are simulated using a step pedal input to full load from the optimized part load points and total rise times are analyzed. For conventional non-FVVT configurations it has been demonstrated that part load cases with higher EGR rates concluded significantly higher T10 (time to 10% of BMEP) values, while T90 (time to 90% of BMEP) and T10-90 (time between 10% and 90% of BMEP) at the tip-in transient were least influenced by residual content. Assuming a Pareto optimal front, this leads to propose that advanced valve control strategies enabled by FVVT technologies, targeting maximum scavenging and optimized EGR rates, are capable of eliminating the potential burden that is turbocharger lag, otherwise sustained in boosted engines as a result of limited cam-based valvetrains, on tip-in transient events from a minimum BSFC steady state part load initial condition.</div></div>
10
Serrano, José Ramón, Francisco José Arnau, Joaquín De la Morena, Alejandro Gómez-Vilanova, Stephane Guilain e Samuel Batard. "A Methodology to Calibrate Gas-Dynamic Models of Turbocharged Petrol Engines With Variable Geometry Turbines and With Focus on Dynamics Prediction During Tip-in Load Transient Tests". In ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/gt2020-15169.
Abstract (sommario):
Abstract The variable geometry turbines (VGT) technology has been proved as beneficious for diesel engines turbocharging, becoming the standard for passenger car diesel engines when high boosting pressure and short transient response are pursued. It has not been until recent times that OEMs and turbocharger manufacturers are able to explore the advantages of VGTs in petrol engines. The high exhaust gases temperature and the low boost pressure prevented the introduction of petrol VGTs up to now. In modern direct injection petrol engines relevant fuel consumption benefits have been obtained from significant to moderate boosting pressure (thanks to downsizing strategies). This benefit joint with the advances in materials and turbocharger cooling technologies have fostered exploring the limits of VGT technology in petrol engines. Consequently, the 1-D and gas-dynamic modelling of turbocharged petrol engines for matching, benchmarking or analysis purposes has become a significantly more complex task. The reason is the energy loop interaction between VGT, petrol engine and compressor; which makes that all relevant system variables (boosting pressure, back-pressure, VGT inlet gas temperature, residuals, volumetric efficiency, etc) are coupled among them. In this case, a proper simulation strategy of the whole system with existing 1-D gas-dynamic codes, i.e.: avoiding excessive use of spurious-non-physical fitting coefficients, has not been enough explored either described in the literature yet. In addition, proper models of the turbocharger (both compressor and VGT) are more relevant now, since the VGT mechanism is a new variable with a first order influence. It can be destabilizing or tricking the whole system, depending on the engine operative conditions and turbo-model quality. In this paper, a systematic methodology, with physical perspective, for calibrating 1D codes of petrol engines with VGTs is clearly described. The methodology can be easily followed by other engineers or researchers in their modelling activities. In addition, the importance of the turbocharger sub-model for achieving successfully previous objectives is depicted. Standard characteristic maps used as look-up tables are shown to be a poor source of information when compared with pre-processed adiabatic and extrapolated maps. The focus is kept in low end torque at full load steady state and transient tip-in, for being the most challenging situations. Being, low-end torque simulation in steady state the baseline point for the transient simulation.