Alcohols have been used as a fuel for engines since 19th century. Among the various alcohols, ethanol is known as the most suited renewable, bio-based and ecofriendly fuel for spark-ignition (SI) engines. The most attractive properties of ethanol as an SI engine fuel are that it can be produced from renewable energy sources such as sugar, cane, cassava, many types of waste biomass materials, corn and barley. In addition, ethanol has higher evaporation heat, octane number and flammability tempera...
Last. E. Van den Bulck(Katholieke Universiteit Leuven)H-Index: 15
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This paper discusses the minimization of the fuel consumption of a gasoline engine through dynamic optimization. The minimization uses a mean value model of the powertrain and vehicle. This model has two state variables: the pressure in the engine intake manifold and the engine speed. The control input is the throttle valve angle. The model is identified on a universal engine dynamometer. Optimal state and control trajectories are calculated using Bock's direct multiple shooting method, implemen...
We present accurate low-dimensional models for real time simulation, control, and optimization of monolithic catalytic converters used in automobile exhaust treatment. These are derived directly by averaging the governing equations and using the concepts of internal and external mass transfer coefficients. They are expressed in terms of three concentration and two temperature modes and include washcoat diffusional effects without using the concept of the effectiveness factor. The models reduce t...
The purpose of this study is to experimentally analyse the performance and the pollutant emissions of a four-stroke SI engine operating on ethanol-gasoline blends of 0%, 5%, 10%, 15% and 20% with the aid of artificial neural network (ANN). The properties of bioethanol were measured based on American Society for Testing and Materials (ASTM) standards. The experimental results revealed that using ethanol-gasoline blended fuels increased the power and torque output of the engine marginally. For eth...
Abstract ‘Multi-zone thermodynamic engine model’ is a generic term adopted here for the type of model also referred to as quasi-dimensional, two-zone, three-zone, etc.; based on the laws of mass and energy conservation and using a mass burning rate sub-model (as opposed to a prescribed mass burning rate) to predict the in-cylinder pressure and temperature throughout the power cycle. Such models have been used for about three decades and provide valuable tools for rapid evaluation of the influenc...
Abstract Ethanol produced from biomass has high octane number and gives lower emissions. Therefore, it is used as alternative fuel in the gasoline engines. In this study, ethanol was used as fuel at high compression ratio to improve performance and to reduce emissions in a small gasoline engine with low efficiency. Initially, the engine whose compression ratio was 6/1 was tested with gasoline, E25 (75% gasoline + 25% ethanol), E50, E75 and E100 fuels at a constant load and speed. It was determin...
Presented in this paper is a feedforward fueling controller identification methodology for the transient fueling control of spark ignition (SI) engines. The hypothesis of this work is that the feedforward fueling control of SI engines can be separated into steady state and transient phenomena and that the majority of the nonlinear behavior associated with engine fueling can be captured with nonlinear steady state models. The proposed transient controller identification process is built from stan...
The effects of ethanol addition to gasoline on an SI engine performance and exhaust emissions are investigated experimentally and theoretically. In the theoretical study, a quasi-dimensional SI engine cycle model, which was firstly developed for gasoline-fueled SI engines by author, has been adapted for SI engines running on gasoline–ethanol blends. Experimental applications have been carried out with the blends containing 1.5, 3, 4.5, 6, 7.5, 9, 10.5 and 12vol% ethanol. Numerical applications h...
Abstract A novel approach is used to derive a low-dimensional model for a CSTR by spatial averaging of the three dimensional convection–diffusion reaction (CDR) equations. For the isothermal case, the model may be expressed in the two-mode form as d 〈 C 〉 d t + R ( 〈 C 〉 ) = 1 τ c ( C m in - C m ) ; C m - 〈 C 〉 = 1 τ c ( t mix , 2 C m in - t mix , 1 C m ) , where 〈 C 〉 and C m are the spatial average and cup-mixing concentrations, while τ c , t mix , 1 and t mix , 2 are the space time and mixing...
#1Henry J. Curran(LLNL: Lawrence Livermore National Laboratory)H-Index: 90
#2P. Gaffuri(LLNL: Lawrence Livermore National Laboratory)H-Index: 5
Last. Charles K. Westbrook(LLNL: Lawrence Livermore National Laboratory)H-Index: 88
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A detailed chemical kinetic mechanism has been developed and used to study the oxidation of iso-octane in a jet-stirred reactor, flow reactors, shock tubes and in a motored engine. Over the series of experiments investigated, the initial pressure ranged from 1 to 45 atm, the temperature from 550 K to 1700 K, the equivalence ratio from 0.3 to 1.5, with nitrogen-argon dilution from 70% to 99%. This range of physical conditions, together with the measurements of ignition delay time and concentratio...
#1Zheng Zong(CAS: Chinese Academy of Sciences)H-Index: 11
#2Zeyu Sun(CAS: Chinese Academy of Sciences)H-Index: 1
Last. Gan Zhang(CAS: Chinese Academy of Sciences)H-Index: 87
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Nitrogen isotope (δ15N) monitoring is a potentially powerful tool in tracing atmospheric nitrogen oxides (NOx); however, the isotopic fingerprint of vehicle exhaust remains poorly interpreted. This deficiency limits our understanding of the origin of atmospheric haze pollution, especially in China. In this study, we systemically explored the δ15N-NOx fingerprints of various vehicle exhausts (n = 137) in China. The δ15N-NOx values of vehicle exhausts ranged from -18.8‰ to +6.4‰, presenting a sign...
#1Sunil K. Rawat(IITD: Indian Institute of Technology Delhi)
#2Vaibhav Srivastava(IITD: Indian Institute of Technology Delhi)H-Index: 5
Last. Divesh Bhatia(IITD: Indian Institute of Technology Delhi)H-Index: 8
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Abstract The kinetics of NO formation is used to study the effect of NO injected into a hydrogen engine on its emission characteristics. Considering the engine to be a variable-volume reactor, it is shown that the injection of NO reduces its further formation. In contrast to the earlier studies, it is highlighted that a reduction in the amount of NO can be achieved even if the reactions between the fuel and NO do not take place. Additionally, the predicted reduction in NO is not due to the lower...
#2Divesh Bhatia(IITD: Indian Institute of Technology Delhi)H-Index: 8
Abstract A global kinetics based model is developed for a spark ignited single cylinder H2 engine for prediction of NO emissions, using mass and energy conservation equations. Based on literature experimental data, a transient spark energy delivery model is developed. A comprehensive heat transfer model is used which considers the heat losses by a combination of forced convection, conduction and natural convection using extended surfaces. It is shown that the major resistance to heat transfer in...
In this work, we develop low-dimensional models to describe steady-state mass transfer and reactions in two-phase stratified flow in microchannels. The partial differential equations that consider the effect of axial convection, transverse diffusion, and reaction are averaged in the transverse direction using the Lyapunov–Schmidt method. The resulting reduced-order model describes the evolution of the cup-mixing average and cross-section average concentrations along the axial direction. Two diff...
Abstract A physics based one-dimensional transient seven partial differential equation model is proposed to study the oxygen storage dynamics and cold start behavior of a three-way catalytic converter. The model uses the recently published simplified kinetic model, is computationally efficient and may be used for offline TWC outer loop controller design and validation. The proposed TWC model is validated using emissions data collected in a vehicle over multiple drive cycles including FTP cycles....
Abstract This paper presents a parametric study on instantaneous heat transfer of a direct-injection hydrogen-fueled engine using a multidimensional model. A simplified single-step mechanism was considered for estimating the reaction rate of hydrogen oxidation. The modified wall-function was used for resolving the near-wall transport. An arbitrary Lagrangian–Eulerian algorithm was adopted for solving the governing equations. Experimental measurements were implemented to verify the developed mode...