Academic literature on the topic 'Flight phase prediction'
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Journal articles on the topic "Flight phase prediction"
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Wang, Ziming, Chaohao Liao, Xu Hang, Lishuai Li, Daniel Delahaye, and Mark Hansen. "Distribution Prediction of Strategic Flight Delays via Machine Learning Methods." Sustainability 14, no. 22 (November 16, 2022): 15180. http://dx.doi.org/10.3390/su142215180.
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Predicting flight delays has been a major research topic in the past few decades. Various machine learning algorithms have been used to predict flight delays in short-range horizons (e.g., a few hours or days prior to operation). Airlines have to develop flight schedules several months in advance; thus, predicting flight delays at the strategic stage is critical for airport slot allocation and airlines’ operation. However, less work has been dedicated to predicting flight delays at the strategic phase. This paper proposes machine learning methods to predict the distributions of delays. Three metrics are developed to evaluate the performance of the algorithms. Empirical data from Guangzhou Baiyun International Airport are used to validate the methods. Computational results show that the prediction accuracy of departure delay at the 0.65 confidence level and the arrival delay at the 0.50 confidence level can reach 0.80 without the input of ATFM delay. Our work provides an alternative tool for airports and airlines managers for estimating flight delays at the strategic phase.
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Intano, Gabriel P., and William R. Howse. "Predicting Performance in Army Aviation Flight Training." Proceedings of the Human Factors Society Annual Meeting 36, no. 12 (October 1992): 907–10. http://dx.doi.org/10.1518/107118192786750304.
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The Army Research Institute Aviation Research and Development Activity successfully implemented the Multi-Track Test Battery (MTTB) and associated classification functions in 1988. The battery and functions have been used to assign flight students to their combat skills aircraft. The present program determined the applicability of the battery to prediction of student performance in flight training. Performance evaluation in training consists of flight phase grades and academic phase grades. In addition to these grades, Overall Average Grade and Overall Flight Grade were also predicted using Forward Stepwise Multiple Regression procedures. Stepwise Multiple Discriminant Analysis was used to investigate two additional measures, flight deficiency training setback and flight deficiency attrition.
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Bramble, William J., and Jefferson M. Koonce. "The Path to Airline Employment: Flight Experience and Performance in a Full-Mission Flight Simulation." Proceedings of the Human Factors and Ergonomics Society Annual Meeting 42, no. 11 (October 1998): 797–800. http://dx.doi.org/10.1177/154193129804201106.
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Commercial pilots were studied in order to determine whether systematic relationships existed between composition of flight experience and performance deficiencies during a performance evaluation in a flight simulator. Flight experience variables included: (a) multi-engine (ME) time, (b) Part 121/135 time, (c) instrument time, and (d) percentage of flight hours acquired as an instructor. A composite performance measure was generated by summing evaluator ratings across all eight phases of flight and all four task categories. Separate measures were generated from the evaluation rating form for each phase of flight and each task category as well. Errors were most common during the approach, arrival, and holding phases of flight. Errors involving control and navigation were more frequent than errors involving communication or configuration. Correlational methods were used to analyze relationships between experience and overall performance. Only ME and Part 121/135 time contributed significantly to prediction of performance in the simulator ( R = 0.42, p < 0.001). ME and Part 121/135 flight experience were associated with better performance during the arrival and approach phases of flight and with better aircraft control. ME experience was uniquely associated with better performance during the holding phase of flight and with configuration and navigation performance. Part 121/135 experience were uniquely associated with better performance during the takeoff and enroute phases of flight and with superior communication. Implications for pilot selection are discussed.
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Xiang, Zheng, Wenqi Zhang, Deyang He, and Yu Tang. "A Centralized Algorithm with Collision Avoidance for Trajectory Planning in Preflight Stage." International Journal of Aerospace Engineering 2021 (January 6, 2021): 1–10. http://dx.doi.org/10.1155/2021/6657464.
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In order to better understand pretactical phase flow management with the flight plan centralized processing at its core, based on the flight plan centralized processing system and track-based operation, the aircraft’s 4D trajectory planning challenges require a deeper level of analysis. Firstly, through establishing a flight performance prediction model, in which the flight plan data is extracted and the time when an aircraft passed a specified waypoint is calculated, a 4D flight prediction can be derived. Secondly, the air traffic flow of the waypoint is calculated, and a converging point along a flight route is selected. Through adjusting the time and speed of the aircraft passing this point, conflict between aircraft is avoided. Finally, the flight is verified by CCA1532, with the connecting flight plan centralized processing center set in line with the company’s requirements. The results demonstrate that according to flight plans, the 4D trajectory of the aircraft can be predicted with the nearest minute and second, and the flow of a total of 20 aircraft within one hour before and after the passage of CCA1532 at key point WADUK can be calculated. When there is a conflict of 88 s between the convergence point and flight B, the speed of B aircraft is adjusted from 789 km/h to 778 km/h, and the time of passing the WADUK point is increased by 7 s, thereby realizing the conflict-free trajectory planning of the two flights.
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Xiang, Zheng, Wenqi Zhang, Deyang He, and Yu Tang. "A Centralized Algorithm with Collision Avoidance for Trajectory Planning in Preflight Stage." International Journal of Aerospace Engineering 2021 (January 6, 2021): 1–10. http://dx.doi.org/10.1155/2021/6657464.
Full textAbstract:
In order to better understand pretactical phase flow management with the flight plan centralized processing at its core, based on the flight plan centralized processing system and track-based operation, the aircraft’s 4D trajectory planning challenges require a deeper level of analysis. Firstly, through establishing a flight performance prediction model, in which the flight plan data is extracted and the time when an aircraft passed a specified waypoint is calculated, a 4D flight prediction can be derived. Secondly, the air traffic flow of the waypoint is calculated, and a converging point along a flight route is selected. Through adjusting the time and speed of the aircraft passing this point, conflict between aircraft is avoided. Finally, the flight is verified by CCA1532, with the connecting flight plan centralized processing center set in line with the company’s requirements. The results demonstrate that according to flight plans, the 4D trajectory of the aircraft can be predicted with the nearest minute and second, and the flow of a total of 20 aircraft within one hour before and after the passage of CCA1532 at key point WADUK can be calculated. When there is a conflict of 88 s between the convergence point and flight B, the speed of B aircraft is adjusted from 789 km/h to 778 km/h, and the time of passing the WADUK point is increased by 7 s, thereby realizing the conflict-free trajectory planning of the two flights.
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Durrant, J. T., William Doebler, Alexandra Loubeau, Mark C. Anderson, and Kent L. Gee. "Comparison and regression analysis of lateral sonic boom measurements and PCBoom predictions." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A126. http://dx.doi.org/10.1121/10.0015767.
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NASA plans to fly the X-59 aircraft over communities to gather data on the response to quiet supersonic flight. This data campaign could revolutionize the aerospace industry by enabling commercial, overland supersonic flight. To prepare for this campaign, NASA is developing PCBoom, a software suite of sonic boom modeling tools. PCBoom-predicted Perceived Level (PL) values were previously compared with measured PL values from a recent NASA test flight campaign, Quiet Supersonic Flights 2018 (QSF18), and were found to differ by an average of 6 dB. This work investigates the PCBoom prediction performance using data from NASA’s 2020 CarpetDIEM Phase I flight test using an F-18 aircraft. PL predictions are compared using the PCBoom default F-18 F-function near-field as input versus a computational fluid dynamics near-field solution for the aircraft as input. To investigate potential sources of metric variability and differences between modeled and measured metrics, Least Absolute Shrinkage and Selection Operator (LASSO) and least-squares regression are used. Because weather has a strong influence on sonic boom variability, the regression techniques are also used to guide the necessary number of ground weather measurements to capture boom metric variability. [Work supported by NASA Langley Research Center through the National Institute of Aerospace.]
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Thotawaththa, Pramesh Chathushka, and A. W. S. Chandana. "Effectiveness of the biomechanical factors related to triple jump performance prediction during COVID 19 period in sri lanka." South Florida Journal of Development 3, no. 1 (February 21, 2022): 1351–59. http://dx.doi.org/10.46932/sfjdv3n1-104.
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The triple jump is an athletic event consisting of three phases which are hop, step, and jump. According to the reversibility training method, that reveals when these athletes can’t be able to maintain their physical fitness and performance properly, it influences for their performance negatively. This study was to identify how the athletes maintain the performances and how they obtain the performance prediction using the biomechanical method during the COVID-19 period in Sri Lanka. Those data were collected from five National standard male triple jumpers. The mean age of the participants is 26. The triple jump technique was done by using the dynamic equation which included kinematic variables for flight phase of the above three phases. The Matlab17 software was used to optimize the flight phase. Three cameras (100Hz) were used to observe the coordinates of center of mass and kinematics variables on the sagittal plane. The videos were analyzed through the Kinovea (0.9.3 version) software. The hop dominated balance technique (35.5: 30.4: 34.1) was used for the prediction. The previous performances values of the players were 14.32m to 16.07m (Before 2020). Current COVID-19 period performances were 13.13m to 15.43m. The velocity and angle were optimized by 5% and +20 outcome of the players were more than 16m. Considering this study, athletes’ phases weren’t in the optimum phase ratio. The hop dominated balance performance prediction and players’ current and previous performances were significantly different in this study. Through this research all coaches and athletes can identify their shortcoming phase and values of the optimization variables and prediction performance level. If not, coaching techniques and tactics can be modified.
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Amaro Carmona, Manuel Angel, Darius Rudinskas, and Cristina Barrado. "DESIGN OF A FLIGHT MANAGEMENT SYSTEM TO SUPPORT FOUR-DIMENSIONAL TRAJECTORIES." Aviation 19, no. 1 (March 30, 2015): 58–65. http://dx.doi.org/10.3846/16487788.2015.1015284.
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This paper presents the design and simulation of the functions of a flight Management System (FMS) in order to follow four-dimensional trajectories automatically. This is achieved by controlling the aircraft’s airspeed, altitude, heading and vertical speed in order to arrive to the merging point in a specified time. The system receives data from the aircraft and computes new control parameters based on mathematical equations and algorithms of prediction trajectories. Additional features have been added to the FMS-4D, such as the capability of predicting the arrival time taking into account previous flight parameters and speed/altitude constrains. Finally, a testing phase was carried out using a flight simulator in order to obtain the performance and results of the designed system.
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Yeo, Hyeonsoo, and Robert A. Ormiston. "UH-60A Airloads Workshop—Setting the Stage for the Rotorcraft CFD/CSD Revolution, Part I: Background and Initial Success." Journal of the American Helicopter Society 67, no. 2 (April 1, 2022): 1–17. http://dx.doi.org/10.4050/jahs.67.022010.
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The UH-60A Airloads Workshop was a unique collaboration of aeromechanics experts from the U.S. Government, industry, and academia to address technical issues that hindered accurate rotor loads predictions. The Airloads Workshop leveraged the NASA/Army UH-60A Airloads flight test and NFAC wind tunnel test data. It functioned continuously for 17 years, from 2001 to 2018, and brought about one of the most important advancements in rotorcraft aeromechanics prediction capabilities by successfully demonstrating high-fidelity coupled computational fluid dynamics (CFD) and computational structural dynamics (CSD) analyses for both steady and maneuvering flight. The article is divided into two parts. Part I surveys the background of rotorcraft CFD/CSD development difficulties, the origins of the Airloads Workshop, and the rapid success achieved during the first phase that consisted of eight Workshops. Part II describes ongoing development during the subsequent two phases of the Airloads Workshop, the Ninth through the 13th, and the 14th through the 31st Workshops; the impact of the Airloads Workshop; and the lessons learned. Part I surveys the technical activities that led to a breakthrough for CFD/CSD coupling to successfully predict rotor blade airloads in trimmed steady-level flight conditions. This success illustrated the importance of collaboration among key experts with diverse backgrounds focused on a common objective to advance rotorcraft prediction methods.
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Jung, JaeKyung, and DongHwan Hwang. "Impact Point Prediction of the Ballistic Target Using a Flight Phase Discrimination." Journal of the Korea Institute of Military Science and Technology 18, no. 3 (June 5, 2015): 234–43. http://dx.doi.org/10.9766/kimst.2015.18.3.234.
Full textBook chapters on the topic "Flight phase prediction"
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Qiu, Ju, and Chaofeng Liu. "Verification and Validation of Supersonic Flutter of Rudder Model for Experiment." In Optimization Problems in Engineering [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.98384.
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The abrupt and explosive nature of flutter is a dangerous failure mode, which is closely related to the structural modes. In this work, the principal goal of the study is to produce the model, which is used very accurately for flutter predictions. Mode correctness of the model can correct the test deflects by the optimization technique----Sequential Quadratic Programming (SQP). The optimization of two finite element models for two flight conditions, transonic and supersonic speeds, had the different objectives which were defined by the nonlinear and linear eigenvector errors. The first and second frequencies were taken as constraints. And the stiffness of the rotation shaft was also restricted to some limits. The stiffness of the rudder axle was defined as design variables. Experiments were performed for considering springs both in plunge and in torsion of the rudder shaft. When the comparison between experimental information and analyzed calculations is described, generally excellent agreement is obtained between experimental and calculated results, and aeroelastic instability is predicted that agrees with experimental observations. Comments are also given concerning improvements of the flutter speed to be made to the model with changing stiffness of the rudder axle. Most importantly, V&V Method is used to provide the confidence in the results from simulation in this paper. Firstly, it introduces experimental data from Ground Vibration Test to build up or modify the Finite Element Model, during the Verification phase, which makes simulated models closer to the real world and guarantees satisfaction of final computed results to requirements, such as airworthiness. Secondly, the flutter consequence is validated by wind tunnel test. These enhancements could find potential applications in industrial problems.
Conference papers on the topic "Flight phase prediction"
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Moushegian, Alex, Daniel Wachspress, Marilyn Smith, and Glen Whitehouse. "Hover Performance in Ground Effect Prediction Using a Dual Solver Computational Methodology." In Vertical Flight Society 77th Annual Forum & Technology Display. The Vertical Flight Society, 2021. http://dx.doi.org/10.4050/f-0077-2021-16715.
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Rotorcraft operation in ground effect is an essential phase of every rotorcraft mission. Accurate prediction of this aerodynamic regime has implications for the design of the rotor, vehicle, and mission guidelines. Modern rotorcraft designs require higher fidelity predictions of the aerodynamics beyond the capabilities of momentumbased or algebraic models of ground effect, but high-fidelity computational fluid dynamics (CFD) remains intractably expensive. A hybrid CFD-free-wake solver OVERFLOW-CHARM has been developed for application to this problem. It was validated against thrust, power, and flow visualization data obtained experimentally for a micro-scale rotor hovering out of ground effect and in ground effect at a range of heights between h/R = 0.5 and h/R = 2.5. A study of numerical options was performed to ensure confidence in the computational simulations. The results demonstrated that OVERFLOW-CHARM was able to capture the integrated rotor loads within three percent of a conventional OVERFLOW simulation at twenty percent the computational cost, and that qualitative agreement in the predicted flow fields was observed between OVERFLOW-CHARM, OVERFLOW, and experiment.
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Dayhoum, Abdallah, Mohamed Y. Zakaria, and Omar E. Abdelhamid. "Unsteady Aerodynamic Modeling and Prediction of Loads for Rotary Wings in Forward Flight." In ASME 2019 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/detc2019-97531.
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Abstract In this effort, a new approach in aerodynamic modeling that accounts for unsteady wake effects as well as viscous friction drag, Leading edge suction effect and post stall behavior for rotary wings in forward flight is proposed. The adopted approach commingles the unsteadiness with the problem of helicopter rotor blade in forward flight. The results of the local normal force coefficients were compared with experimental results of the 7A rotor case study in high speed test point 312 at five non-dimensional radial positions. A CFD solver, HOST/elsA, results are compared with the obtained results at five radii locations. The results show a good agreement between the experimental results and the proposed model preserving the same pattern of variation along the azimuth angle with a slight discrepancy for amplitude and phase angle. Of particular interest, the presented model showed better agreement with the experimental for higher radii locations.
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Crawford, Aaron, and Marilyn Smith. "Physics and Improved Simulations for Computational Modeling of Synthetic Jets." In Vertical Flight Society 78th Annual Forum & Technology Display. The Vertical Flight Society, 2022. http://dx.doi.org/10.4050/f-0078-2022-17582.
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With the rise of active flow control techniques several approaches of flow reattachment have been studied, including the use of direct momentum injection through a zero-net mass flow synthetic jet. The focus of this paper is to further understand the role of turbulence in the physics of synthetic jets and the sensitivity of external crossflow on the prediction of the jet and its downstream behavior while in cross flow. Computational results are correlated with recent experimental data obtained by the U.S. Army. The full actuator geometry is computationally modeled and to develop unsteady and phase-averaged boundary conditions at the jet/outer mold line interface at the relevant spatial and temporal levels. This study also considers the effect of turbulence model, as well as the associated turbulent quantities, and their influence in the prediction of the local synthetic jet flowfield in cross flow. Results indicate that turbulent fluctuations in three-dimensional flows with large eddy simulation wakes are required to predict the jet interactional effects. The external crossflow has a significant impact on the magnitude of the turbulent characteristics, but the trends observed in experiments are captured with the additional of turbulence in the jet.
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Gan, Ze, Mrunali Botre, Kenneth Brentner, Eric Greenwood, Joseph Horn, Bhaskar Mukherjee, and Jean-Pierre Theron. "A New Distributed Electric Propulsion Aircraft Simulation Tool for Coupled Flight Dynamics, Free Wake, and Acoustic Predictions." In Vertical Flight Society 77th Annual Forum & Technology Display. The Vertical Flight Society, 2021. http://dx.doi.org/10.4050/f-0077-2021-16693.
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A major barrier to certification and public acceptance of emerging distributed electric propulsion (DEP) aircraft is their noise. Like conventional helicopters, accurate noise prediction of DEP aircraft requires accurate modeling of realistic flight dynamics and controls. Furthermore, aspects unique to DEP aircraft must be modeled, such as variable rotor speed for thrust control, and unsteady aerodynamics arising from rotor thrust control and aerodynamic interactions between rotors and the airframe. To address these needs, this paper describes the development and software coupling of a noise prediction system for DEP aircraft. This system is demonstrated for maneuvering flight simulations consisting of a roll attitude doublet in low speed forward flight, for two rotor thrust control schemes: variable rotor speed and variable collective pitch. Loading noise levels for this configuration generally exceeded thickness noise levels. For a single rotor, loading noise modulated with thrust, regardless of the cause of the time variation of loading (variable rotor speed or collective pitch). However, the range of modulation was greater for the variable rotor speed case than for variable pitch. Less modulation is observed in the total noise for all rotors, because the rotor thrusts must vary to balance the aircraft. Interference patterns are observed for the constant speed case due to coherent phase relations between the rotors, whereas the noise of the variable speed rotors does not add coherently.
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Lavergne, K., V. Quintilla, R. Lecourt, and G. Lavergne. "Experimental and Numerical Study of Spray Ignition for In-Flight Re-Light." In ASME 2002 Joint U.S.-European Fluids Engineering Division Conference. ASMEDC, 2002. http://dx.doi.org/10.1115/fedsm2002-31233.
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The context of this study is the prediction of re-ignition for turbojet engines after in-flight extinction at high altitude. Experiments have been performed on a simple geometry of a combustion chamber to test ignition at ambient conditions for three positions of the spark plug. Then, the two-phase flow corresponding to the experimental configuration has been simulated with the eulerian-lagrangian code used at ONERA. In parallel, a time dependent 0-dimensional model has been developed to predict the ignition of a cluster composed of fuel droplets when it is submitted to the spark inside the combustion chamber. This model has been applied on the two-phase flow computation in three elementary volumes located close to different spark plug positions. Ignition has been tested numerically for these clusters of drops, whose characteristics are dependent of their location in the combustion chamber, as well as, of the two-phase flow configuration in the geometry. Comparisons between experimental and numerical results are presented in this paper.
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Pham, Loan (Joan), and John Hewitt. "A Method to Reduce Rotorcraft Development Risk by Integrating Historical Quantitative Risk Assessment into Fault Tree Models." In Vertical Flight Society 78th Annual Forum & Technology Display. The Vertical Flight Society, 2022. http://dx.doi.org/10.4050/f-0078-2022-17613.
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Fault Tree Analysis (FTA) is performed during vertical lift product development, but only an estimation of the probability of component failures can be made at that point of product design and development. Estimation of component failure probability during FTA typically does not account for component aging, installation effects, maintenance actions, and other factors encountered in operation, which can lead to under prediction, resulting in identification of hazards during test, evaluation, and deployment. Quantitative Risk Assessment (QRA) is typically performed during fleet operation. Efforts to eliminate hazards or mitigate risks are less effective and much more costly in this phase of the product lifecycle compared to proactively addressing hazards early in development. If the risk of failures could be accurately predicted earlier, hazards could be addressed early in the process. Such a method is presented here, where historical QRA for similar hazards can be integrated into the FTA. This would reduce cost, schedule, and safety risks by reducing the risk of failure during ground and flight test and in fleet operation.
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Harnik, Ron S., and Herman D. Haustein. "First-Order Model of Free-Jet Hydrodynamic Evolution for Heat Transfer Prediction, Including Nozzle and Flow Rate Effects." In ASME 2016 Heat Transfer Summer Conference collocated with the ASME 2016 Fluids Engineering Division Summer Meeting and the ASME 2016 14th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/ht2016-7388.
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Jet impingement flow is known to generate one of the highest single-phase heat transfer rates, with potential for micro-electronics cooling applications. Although free-surface jets have been studied extensively, existing models are either too complex for practical use or do not consider all relevant parameters, such as the impinging jet’s velocity profile. Recently the authors have shown that the stagnation zone heat transfer is dictated by the jet’s centerline velocity upon impingement, and that going between the limiting cases (uniform vs. parabolic profiles, laminar flow) corresponds to a two-fold increase in heat transfer. In the present study, which is motivated by cooling at micro-scales (predominantly laminar flows), this simplified analysis is extended leading to a first-order analytical approximation, which is valid not only for the limiting cases but over the entire profile range. Thereby, the development of the jet flow both in the nozzle (pipe-type) and subsequently during its flight (before impingement) is incorporated in this model over a broad range of parameters. For validation of the model, as well as for additional insight into the governing physics, direct numerical simulations were conducted. Through which it is shown that the jet’s velocity profile and its evolution during free “flight” are dependent on the level of the flow’s upstream development in the nozzle, both of which depend on a single self-similar scale: distance travelled normalized by the nozzle diameter and Reynolds number. This one-way coupling requires incorporation of both stages of development for an accurate description, as done in the present model. During pipe-flow, the first-order model employs a more-rapid development rate than during jet-flight (due to the additional pressure-driven flow) — converging to more complex, well-known models, within a few pipe diameters (for Re = 200 to 2300). During flight, the model describes velocity profile relaxation, which is dominated by viscous diffusion and assisted by jet contraction. Jet contraction is dependent on the emerging velocity profile and liquid-vapor surface tension. For most relevant conditions surface tension is negligible, under which the first-order model centerline velocity decay prediction agrees well with both present simulations and previous works. Thereby, the present work lays the foundation for a simpler, more useable model for predicting heat transfer under an impinging free-surface jet, over a wide range of conditions (various liquids, pipe-type nozzles of different lengths, flow-rates and nozzle-to-plate distances), as part of an ongoing study into micro-jet array heat transfer.
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Parthasarathy, Girija, and Satyavaraprasad Allumallu. "Reduced Models for Rotating Component Lifing." In ASME Turbo Expo 2004: Power for Land, Sea, and Air. ASMEDC, 2004. http://dx.doi.org/10.1115/gt2004-53993.
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The most common failure mode for engine rotating components is material fatigue. Low Cycle Fatigue or LCF is caused by stresses and temperatures resulting from start-stop cycles. One current common practice is to assign an LCF life of certain number of start-stop cycles based on a standard flight or mission. This is done during design through detailed calculations of stresses and temperatures for a standard flight, and the use of material property and failure models. The limitation of the design phase stress and temperature calculations is that they cannot take into account actual operating temperatures and stresses. In order to improve significantly the accuracy of the LCF lifing prediction, the component temperatures and stresses need to be computed for the actual operating conditions. However, stress and thermal models are very detailed and complex, and it could take on the order of a few hours to complete a stress and temperature simulation for a flight. The objective of this work is to develop reduced models, that would enable us to compute the stresses and temperatures at critical locations, without the detailed computationally intensive models. This paper describes the development of the reduced model and the results achieved in comparison with the original models for components of Honeywell propulsion engines. Given certain inputs such as engine speed and ambient temperature for the duration of the flight, the reduced models computes the component critical location temperature and thermal stress for the same flight in a very small fraction of time it would take the original finite element model to compute.
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Parthasarathy, Girija, Sunil Menon, Kurt Richardson, Ahsan Jameel, Dawn McNamee, Tori Desper, Michael Gorelik, and Chris Hickenbottom. "Neural Network Models for Usage Based Remaining Life Computation." In ASME Turbo Expo 2006: Power for Land, Sea, and Air. ASMEDC, 2006. http://dx.doi.org/10.1115/gt2006-91099.
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In engine structural life computations, it is common practice to assign a life of certain number of start-stop cycles based on a standard flight or mission. This is done during design through detailed calculations of stresses and temperatures for a standard flight, and the use of material property and failure models. The limitation of the design phase stress and temperature calculations is that they cannot take into account actual operating temperatures and stresses. This limitation results in either very conservative life estimates and subsequent wastage of good components, or in catastrophic damage because of highly aggressive operational conditions which were not accounted for in design. In order to improve significantly the accuracy of the life prediction, the component temperatures and stresses need to be computed for actual operating conditions. However, thermal and stress models are very detailed and complex, and it could take on the order of a few hours to complete a stress and temperature simulation of critical components for a flight. The objective of this work is to develop dynamic neural network models, that would enable us to compute the stresses and temperatures at critical locations, in orders of magnitude less computation time than required by more detailed thermal and stress models. This work expands on the work done previously [1] where a linear system identification approach was developed. The current paper describes the development of a neural network model and the temperature results achieved in comparison with the original models for Honeywell turbine and compressor components. Given certain inputs such as engine speed and gas temperatures for the flight, the models compute the component critical location temperatures for the same flight in a very small fraction of time it would take the original thermal model to compute.
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Lee, Ryan, and Jon Gabrys. "Airplane Tire Burst Plume Analysis." In ASME 2005 Pressure Vessels and Piping Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/pvp2005-71662.
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On rare occasion, aircraft tires have burst in flight after being retracted into the wheel well. The burst rapidly releases a high-pressure plume of gas that may cause damage to systems and structure mounted in the wheel well. Since airplanes must be designed to maintain continued safe flight and landing following a tire burst in the wheel well, it is essential that accurate definitions of the plume pressure loads be provided to the airplane structural and systems designers. Existing plume load definitions have been developed over the years from test data and theoretical calculations, but given the very short duration of the event and the complexity of the dynamics involved, it is desired to validate the existing threat definitions through the use of advanced finite element modeling. This paper describes the use of LS-DYNA to accurately predict the pressure plume created from the controlled release of a pressurized tank. This task is considered part of the validation phase. The next step will include the complexities of the deforming tire to quantify the effect of the rapidly changing hole diameter, and to study how the solution diverges from the classical prediction.