The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Eric Domingues - One of the best experts on this subject based on the ideXlab platform.
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Volumetric Efficiency optimization of a single-cylinder D.I. diesel engine using differential evolution algorithm
Applied Thermal Engineering, 2016Co-Authors: Stephan Hennings Och, Luis Mauro Moura, Viviana Cocco Mariani, Leandro Dos Santos Coelho, José Antonio Velásquez, Eric DominguesAbstract:Abstract In this work, a mathematical optimization procedure was used to improve the gas exchange process of a single-cylinder compression ignition naturally aspirated engine. Duct lengths and valve timing were chosen as optimization variables while Volumetric Efficiency was defined as the objective function. Calculations were carried out using a parallelized computational code consisting of (i) a one-dimensional model for the unsteady compressible gas flow taking place in intake and exhaust ducts; (ii) a single-zone combustion model for the in-cylinder processes; and (iii) an optimization routine based on the Differential Evolution technique. Three sets of optimization calculations were conducted. In the first one, the intake duct length was the only optimization variable and it was found that optimal inlet duct lengths vary becoming shorter as engine speed is increased. In the second set of calculations, both intake and exhaust duct lengths have been taken as the optimization variables, and the resulting optimal intake duct lengths were quite similar to those of the first set. In addition, optimal exhaust duct lengths resulted very close in value to optimal intake duct lengths, except at the highest speeds, when the decreasing tendency as engine speed is raised was supplanted by the opposite tendency. In the third set of calculations, the crank angles defining valve synchronism were the optimization variables. It was found that optimal valve timing produced a gain in Volumetric Efficiency, which is similar to that obtained with optimal duct lengths.
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Volumetric Efficiency optimization of a single-cylinder DI diesel engine using differential evolution algorithm
Applied Thermal Engineering, 2016Co-Authors: Luis Mauro Moura, Viviana Cocco Mariani, Leandro Dos Santos Coelho, José Antonio Velásquez, Eric DominguesAbstract:In this work, a mathematical optimization procedure was used to improve the gas exchange process of a single-cylinder compression ignition naturally aspirated engine. Duct lengths and valve timing were chosen as optimization variables while Volumetric Efficiency was defined as the objective function. Calculations were carried out using a parallelized computational code consisting of (i) a one-dimensional model for the unsteady compressible gas flow taking place in intake and exhaust ducts; (ii) a single-zone combustion model for the in-cylinder processes; and (iii) an optimization routine based on the Differential Evolution technique. Three sets of optimization calculations were conducted. In the first one, the intake duct length was the only optimization variable and it was found that optimal inlet duct lengths vary becoming shorter as engine speed is increased. In the second set of calculations, both intake and exhaust duct lengths have been taken as the optimization variables, and the resulting optimal intake duct lengths were quite similar to those of the first set. In addition, optimal exhaust duct lengths resulted very close in value to optimal intake duct lengths, except at the highest speeds, when the decreasing tendency as engine speed is raised was supplanted by the opposite tendency. In the third set of calculations, the crank angles defining valve synchronism were the optimization variables. It was found that optimal valve timing produced a gain in Volumetric Efficiency, which is similar to that obtained with optimal duct lengths. (C) 2016 Elsevier Ltd. All rights reserved.
Gregory M. Shaver - One of the best experts on this subject based on the ideXlab platform.
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Utilizing Production Viable Valve Strategies at Elevated Speeds and Loads to Improve Volumetric Efficiency via Intake Valve Modulation
Frontiers in Mechanical Engineering, 2018Co-Authors: Kalen R Vos, Gregory M. Shaver, James Mccarthy, Lisa FarrellAbstract:Valvetrain flexibility enables the optimization of the engine’s ability to breathe across the operating range, resulting in more efficient operation. The authors have shown the merit of improving Volumetric Efficiency via valvetrain flexibility to improve fuel Efficiency at elevated engine speeds in previous work. This study focuses on production viable solutions targeting similar Volumetric Efficiency benefits via delayed intake valve closure at these elevated engine speeds. Specifically, the production viable solutions include reducing the duration at peak lift, as well as reducing the amount of hardware required to achieve a delayed intake closure timing. It is demonstrated through simulation that delayed intake valve modulation at an elevated speed (2200 RPM) and load (12.7 bar BMEP) is capable of improving Volumetric Efficiency via a production viable lost motion enabled boot profile shape. Phased and dwell profiles were also evaluated. These profiles were compared against each other for two separately simulated cases: 1) modulating both intake valves per cylinder, and 2) modulating one of the two intake valves per cylinder. The boot, phase, and dwell profiles demonstrate Volumetric Efficiency improvements of up to 3.33%, 3.41%, and 3.5% respectively for two valve modulation, while realizing 2.79%, 2.59%, and 3.01% respectively for single valve modulation. As a result, this paper demonstrates that nearly all of the Volumetric Efficiency benefits achieved while modulating IVC via dwell profiles are possible with production viable boot and phased profiles
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Physically based Volumetric Efficiency model for diesel engines utilizing variable intake valve actuation
International Journal of Engine Research, 2011Co-Authors: Lyle Kocher, Ed Koeberlein, D. G. Van Alstine, Karla Stricker, Gregory M. ShaverAbstract:Advanced diesel engine architectures employing flexible valve trains enable emissions reductions and fuel economy improvements. Flexibility in the valve train allows engine designers to optimize the gas exchange process in a manner similar to how common rail fuel injection systems enable optimization of the fuel injection process. Modulating valve timings directly impacts the Volumetric Efficiency of the engine since it directly controls how much mass is trapped in the cylinders. In fact, it will be shown that the control authority of valve timing modulation over Volumetric Efficiency, that is, the range of Volumetric efficiencies achievable due to modulation of the valve timing, is three times larger than the range achievable by modulation of other engine actuators such as the exhaust gas recirculation valve or the variable geometry turbocharger. Traditional empirical or regression-based models for Volumetric Efficiency, while suitable for conventional valve trains, are therefore challenged by flexible v...
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Physically-Based Volumetric Efficiency Model for Diesel Engines Utilizing Variable Intake Valve Actuation
ASME 2011 Dynamic Systems and Control Conference and Bath ASME Symposium on Fluid Power and Motion Control Volume 1, 2011Co-Authors: Lyle Kocher, Ed Koeberlein, D. G. Van Alstine, Karla Stricker, Gregory M. ShaverAbstract:Advanced diesel engine architectures employing flexible valve trains enable emissions reductions and fuel economy improvements. Flexibility in the valve train allows engine designers to optimize the gas exchange process in a manner similar to how common rail fuel injection systems enable optimization of the fuel injection process. Modulating valve timings directly impacts the Volumetric Efficiency of the engine. In fact, the control authority of valve timing modulation over Volumetric Efficiency is three times larger than that due to any other engine actuator. Traditional empirical or regression-based models for Volumetric Efficiency, while suitable for conventional valve trains, are therefore challenged by flexible valve trains. The added complexity and additional empirical data needed for wide valve timing ranges limit the usefulness of these methods. A physically-based Volumetric Efficiency model was developed to address these challenges. The model captures the major physical processes occurring over the intake stroke, and is applicable to both conventional and flexible valve trains. The model inputs include temperature and pressure in the intake and exhaust manifolds, intake and exhaust valve timings, bore, stoke, connecting rod length, engine speed and effective compression ratio, ECR. The model is physically-based, requires no regression tuning parameters, is generalizable to other engine platforms, and has been experimentally validated using an advanced multi-cylinder diesel engine equipped with a flexible variable intake valve actuation system. Experimental data was collected over a wide range of the operating space of the engine and augmented with air handling actuator and intake valve timing sweeps to maximize the range of conditions used to thoroughly experimentally validate the model for a total of 217 total operating conditions. The physical model developed differs from previous physical modeling work through the novel application of ECR, incorporation of no tuning parameters and extensive validation on unique engine test bed with flexible intake valve actuation.Copyright © 2011 by ASME
Luis Mauro Moura - One of the best experts on this subject based on the ideXlab platform.
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Volumetric Efficiency optimization of a single-cylinder D.I. diesel engine using differential evolution algorithm
Applied Thermal Engineering, 2016Co-Authors: Stephan Hennings Och, Luis Mauro Moura, Viviana Cocco Mariani, Leandro Dos Santos Coelho, José Antonio Velásquez, Eric DominguesAbstract:Abstract In this work, a mathematical optimization procedure was used to improve the gas exchange process of a single-cylinder compression ignition naturally aspirated engine. Duct lengths and valve timing were chosen as optimization variables while Volumetric Efficiency was defined as the objective function. Calculations were carried out using a parallelized computational code consisting of (i) a one-dimensional model for the unsteady compressible gas flow taking place in intake and exhaust ducts; (ii) a single-zone combustion model for the in-cylinder processes; and (iii) an optimization routine based on the Differential Evolution technique. Three sets of optimization calculations were conducted. In the first one, the intake duct length was the only optimization variable and it was found that optimal inlet duct lengths vary becoming shorter as engine speed is increased. In the second set of calculations, both intake and exhaust duct lengths have been taken as the optimization variables, and the resulting optimal intake duct lengths were quite similar to those of the first set. In addition, optimal exhaust duct lengths resulted very close in value to optimal intake duct lengths, except at the highest speeds, when the decreasing tendency as engine speed is raised was supplanted by the opposite tendency. In the third set of calculations, the crank angles defining valve synchronism were the optimization variables. It was found that optimal valve timing produced a gain in Volumetric Efficiency, which is similar to that obtained with optimal duct lengths.
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Volumetric Efficiency optimization of a single-cylinder DI diesel engine using differential evolution algorithm
Applied Thermal Engineering, 2016Co-Authors: Luis Mauro Moura, Viviana Cocco Mariani, Leandro Dos Santos Coelho, José Antonio Velásquez, Eric DominguesAbstract:In this work, a mathematical optimization procedure was used to improve the gas exchange process of a single-cylinder compression ignition naturally aspirated engine. Duct lengths and valve timing were chosen as optimization variables while Volumetric Efficiency was defined as the objective function. Calculations were carried out using a parallelized computational code consisting of (i) a one-dimensional model for the unsteady compressible gas flow taking place in intake and exhaust ducts; (ii) a single-zone combustion model for the in-cylinder processes; and (iii) an optimization routine based on the Differential Evolution technique. Three sets of optimization calculations were conducted. In the first one, the intake duct length was the only optimization variable and it was found that optimal inlet duct lengths vary becoming shorter as engine speed is increased. In the second set of calculations, both intake and exhaust duct lengths have been taken as the optimization variables, and the resulting optimal intake duct lengths were quite similar to those of the first set. In addition, optimal exhaust duct lengths resulted very close in value to optimal intake duct lengths, except at the highest speeds, when the decreasing tendency as engine speed is raised was supplanted by the opposite tendency. In the third set of calculations, the crank angles defining valve synchronism were the optimization variables. It was found that optimal valve timing produced a gain in Volumetric Efficiency, which is similar to that obtained with optimal duct lengths. (C) 2016 Elsevier Ltd. All rights reserved.
Aamer Iqbal Bhatti - One of the best experts on this subject based on the ideXlab platform.
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Second order sliding mode observer for estimation of SI engine Volumetric Efficiency & Throttle Discharge Coefficient
2010 11th International Workshop on Variable Structure Systems (VSS), 2010Co-Authors: Qadeer Ahmed, Aamer Iqbal BhattiAbstract:Identification and estimation of non-measurable critical parameters of automotive engine provide significant information to monitor its functions and health. This article proposes a novel estimation scheme of identifying such parameters. Two of the critical parameters are: Volumetric Efficiency and Throttle Discharge Coefficient. These parameters are estimated from the single nonlinear equation of engine inlet manifold pressure dynamics. The estimation scheme utilizes second order sliding mode observer based on super twisting algorithm. Mean Value Engine Model is considered to model the inlet manifold behavior. The estimation is carried out on production vehicle equipped with engine control unit compliant to OBD-II standards. The proposed observer is simple enough for implementation. The estimated parameters have vast application in the area of engine controller design and fault diagnosis/prognosis.
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second order sliding mode observer for estimation of si engine Volumetric Efficiency throttle discharge coefficient
International Workshop on Variable Structure Systems, 2010Co-Authors: Qadeer Ahmed, Aamer Iqbal BhattiAbstract:Identification and estimation of non-measurable critical parameters of automotive engine provide significant information to monitor its functions and health. This article proposes a novel estimation scheme of identifying such parameters. Two of the critical parameters are: Volumetric Efficiency and Throttle Discharge Coefficient. These parameters are estimated from the single nonlinear equation of engine inlet manifold pressure dynamics. The estimation scheme utilizes second order sliding mode observer based on super twisting algorithm. Mean Value Engine Model is considered to model the inlet manifold behavior. The estimation is carried out on production vehicle equipped with engine control unit compliant to OBD-II standards. The proposed observer is simple enough for implementation. The estimated parameters have vast application in the area of engine controller design and fault diagnosis/prognosis.
Mostafa Ghajar - One of the best experts on this subject based on the ideXlab platform.
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A novel Volumetric Efficiency model for spark ignition engines equipped with variable valve timing and variable valve lift Part 1: model development:
Proceedings of the Institution of Mechanical Engineers Part D: Journal of Automobile Engineering, 2016Co-Authors: Amir Hasan Kakaee, Behrooz Mashadi, Mostafa GhajarAbstract:Estimation of the air charge and the Volumetric Efficiency is one of the most challenging tasks in the control of internal-combustion engines owing to the intrinsic complexity and the non-linearity of the gas flow phenomena. In particular, with emerging new technologies such as systems with variable valve timing and variable valve lift, the number of effective parameters increases greatly, making the estimation task more complicated. On the other hand, using a three-way catalyst converter needs strict control of the air-to-fuel ratio to around the stoichiometric ratio, and hence more accurate models are required for estimation of the air charge. Therefore, various models have been proposed in the literature for estimation of the Volumetric Efficiency and the air charge. However, they are either strictly based on physical first principles, making them impractical for conventional applications, or nearly fully empirical and need many experimental data for calibration. In this paper, using a novel approach, ...
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Semi-empirical modeling of Volumetric Efficiency in engines equipped with variable valve timing system
Journal of Central South University, 2016Co-Authors: Mostafa Ghajar, Amir Hasan Kakaee, Behrooz MashadiAbstract:Volumetric Efficiency and air charge estimation is one of the most\ndemanding tasks in control of today's internal combustion engines.\nSpecifically, using three-way catalytic converter involves strict\ncontrol of the air/fuel ratio around the stoichiometric point and hence\nrequires an accurate model for air charge estimation. However, high\ndegrees of complexity and nonlinearity of the gas flow in the internal\ncombustion engine make air charge estimation a challenging task. This is\nmore obvious in engines with variable valve timing systems in which gas\nflow is more complex and depends on more functional variables. This\nresults in models that are either quite empirical (such as look-up\ntables), not having interpretability and extrapolation capability, or\nphysically based models which are not appropriate for onboard\napplications. Solving these problems, a novel semi-empirical model was\nproposed in this work which only needed engine speed, load, and valves\ntimings for Volumetric Efficiency prediction. The accuracy and\ngeneralizability of the model is shown by its test on numerical and\nexperimental data from three distinct engines. Normalized test errors\nare 0.0316, 0.0152 and 0.24 for the three engines, respectively. Also\nthe performance and complexity of the model were compared with neural\nnetworks as typical black box models. While the complexity of the model\nis less than half of the complexity of neural networks, and its\ncomputational cost is approximately 0.12 of that of neural networks and\nits prediction capability in the considered case studies is usually\nmore. These results show the superiority of the proposed model over\nconventional black box models such as neural networks in terms of\naccuracy, generalizability and computational cost.
