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As a new type of energy, free-piston linear generator (FPLG) attracts more research on its stable operation and power performance, while less on its combustion and emission performance. So, in this paper, the emission characteristics of FPLG in two different modes are studied through a port fuel injection (PFI) mode which was verified by the experiment and a gasoline direct injection (GDI) mode. The results showed that: both the GDI mode and the PFI mode produced large amounts of nitrogen oxide (NOx) during the working process. But the GDI mode produced before the PFI mode and it produced nearly 2 times than the PFI mode. However, the formation rate of NOx in GDI mode is much lower than that in PFI mode. Meanwhile, in both modes, 90% of NOX was generated in the cylinder at the temperature higher than 1750K, and only about 10% of NOX was generated at a temperature lower than 1750K.

In order to improve the anti-disturbance performance of engine-load and the effect on speed control for the diesel engine, the paper presents the fuzzy-PID speed control strategy in the architecture of torque-based control. The engine-load estimation algorithm is designed based on the mean-value-model and crankshaft dynamics model, and the estimation precision is validated by engine test in both steady and dynamic conditions. Through the experiment verification of the diesel engine, the fuzzy-PID control strategy based on load estimation can significantly improve the anti-disturbance performance of engine-load in the speed control.

With the development of advanced ABE fermentation technology, the volumetric percentage of acetone, butanol and ethanol in the bio-solvents can be precisely controlled. To seek for an optimized volumetric ratio for ABE-diesel blends, the previous work in our team has experimentally investigated and analyzed the combustion features of ABE-diesel blends with different volumetric ratio (A: B: E: 6:3:1; 3:6:1; 0:10:0, vol. %) in a constant volume chamber. It was found that an increased amount of acetone would lead to a significant advancement of combustion phasing whereas butanol would compensate the advancing effect. Both spray dynamic and chemistry reaction dynamic are of great importance in explaining the unique combustion characteristic of ABE-diesel blend. In this study, a semi-detailed chemical mechanism is constructed and used to model ABE-diesel spray combustion in a constant volume chamber.

Hydrogen fuel is a future energy to solve the problems of energy crisis and environmental pollution. Hydrogen internal combustion engines can combine the advantage of hydrogen without carbon pollution and the main basic structure of the traditional engines. However, the power of the port fuel injection hydrogen engines is smaller than the same volume gasoline engine because the hydrogen occupies the volume of the cylinder and reduces the air mass flow. The turbocharger can increase the power of hydrogen engines but also increase the NOx emission. Hence, a comprehensive controlling strategy to solve the contradiction of the power, BTE and NOx emission is important to improve the performance of hydrogen engines. This paper shows the controlling strategy for a four-stroke, 2.3L hydrogen engine with a turbocharger. The controlling strategy divides the operating conditions of the hydrogen engine into six parts according to the engine speeds and loads.

This present paper described an experimental study on the combustion and emission characteristics of a diesel engine at idle at different altitudes. Five altitudes ranging from 550m to up to 4500m were investigated. Combustion parameters including in-cylinder pressure and temperature, heat release, fuel mass burning and so forth, together with emission factors including CO, HC, NOx and PM were tested and analyzed. The result of on-board measurement manifested that in-cylinder pressure descended consistently with the rising of altitude, while both the maximum in-cylinder temperature and exhaust temperature ascended with the altitude. It was found that ignition delay was lengthened at higher altitude, but the combustion duration became shorter. The crank angle towards 90% fuel burnt has hardly changed with the variation of altitude. As for heat release, the difference of slopes observed at different altitudes was quite slight.

A multidimensional numerical simulation method was developed to analyze air/fuel premixing, stratified combustion and NOx emission formation in a gasoline direct injection (GDI) engine. Firstly, many submodels were integrated into one Computational Fluid Dynamics (CFD) code: ICFD-CN, such as Sarre nozzle flow, Kelvin-Helmholtz (KH) dynamic jet model, Taylor-Analogy Breakup (TAB) model, Rayleigh-Taylor (RT) droplet breakup model, Lefebvre fuel vaporization model, Liu droplet drag & distortion model, Gosman turbulence & droplet dispersion model, O'rourke wall film model, O'rourke and Bracco droplet impinging & coalescence model, Stanton spray/wall impinging model, the Discrete Particle Ignition Kernel(DPIK)ignition model, the single step combustion and the patulous Zeldovich model for NOx generation mechanism. The integrated CFD code was then calibrated against experimental data in a gasoline direct injection engine for several engine operating conditions.

This paper describes an improved mathematical model to study the emission conversion effectiveness of a three-way catalytic converter, which employed detailed chemical reaction mechanism. The model also accounts for adsorption/release of oxygen in the catalyst monolith under non-stoichiometric A/F conditions. A commercial CFD code FLUENT was utilized to solve the governing equations for flow and pressure drop and to simulate the transient process in a three-way catalytic converter in a multi-dimensional manner. A comparison between simulation results and experimental data for a three-way catalyst was conducted and a good agreement was observed. Based on the improved model, some geometric parameters were studied for an elliptic monolith catalyst, which are widely used in today's converter systems because of its advantages in packaging.

A 2-D gas-particle two-phase flow model has been developed to study the flow characteristics in a single channel of a honeycomb ceramic diesel particulate filter. A particle source in cell (PSIC) algorithm is used to calculate the gas-particle two-phase flow. Firstly, the gas-phase flow field alone (without taking into account of the particle-phase) is solved for estimation of gas velocity and pressure fields in the Euler coordinate. Secondly, the particle-phase is added in and particles tracked down in the Lagrange coordinate. Thirdly, the particle source which acts on the gas-phase cell is calculated and added to the gas-phase equations. Fourthly, the gas-phase equations with the particle source are solved again. Lastly, the above process is iterated until the flow field is convergent. Taking the above-mentioned approach, the gas-particle two-phase flow characteristic is simulated using FLUENT. The simulation results are in good agreement with experiment data.

In order to meet the need of high pressure common rail diesel engine, calibration for injection quantity and basic MAP of electronic-controlled injector are made. Combining with testing data, influencing factors for consistency and identity of injecting fuel in electronic-controlled injector are analyzed, in the condition of small quantity, controlled-pressure undulation quantity and injecting pulse revising are presented to achieve the respective demand. Primary basic map for common rail pressure and injecting fuel are fixed with alterable step method, and calibration of fuel quantity MAP is made on bench test. Finally test of electronic-controlled injector equipped in diesel engine is finished, testing result showed that calibration process and method are reasonable.

One-dimensional combustion performance of a turbocharged V-type eight-cylinder diesel engine was computed by used of WAVE code. The parameters of compress ratio, intake temperature, intake pressure, fuel injection quantity, advance angle of injection, fuel injection rate and fuel injection duration were changed so as to study quantificationally how these parameters affect the power, fuel consume, the max combustion pressure, exhaust temperature and emission of the diesel engine. The computational results could help to accomplish the preliminary optimization of several parameters for combustion matching and supplement experimental experience and exploit new products.

In order to achieve simultaneous removal of particulate matters (PM) and NOX in diesel exhaust, a new kind of aftertreatment prototype has been developed. The prototype combined effects of static, cyclone, non-thermal plasma and hydrocarbon selective catalytic reduction. Experiments have been carried out with standard gases simulating diesel exhaust. Physical and chemical effects that took place in the prototype are as follows: the collection of PM by electrostatic-cyclone system, the oxidative combustion of PM, the selective catalytic reduction of NOX, and the reaction between PM and NOX. The effect of non-thermal plasma makes the density of NO decrease and that of NO2 increase, whereas, the amount of NOX remains the same. Employing catalyst coupled with non-thermal plasma debase the temperature by about 50◻, there the peak value of transform rate appears.

A hybrid approach utilizing the measured intake/exhaust port pressure traces and gas dynamics simulation was developed to process the instant fresh charge and RGF (Residual Gas Fraction) trapped in cylinder. The real time RGF, pumping losses and indicated thermal efficiency of an automotive gasoline engine under vehicle driving conditions are analyzed, cycle by cycle, and associated to the engine operating parameters including engine load, speed, VVT positions, manifold pressure and temperatures, as well as spark timing. In this way the inter-relationship among those parameters are established. The derived relationship could be used to determine the in-cylinder process for more accurate prediction of engine performance at the stage of concept simulation study, and applied to narrow the range of parameter tests in the engine calibration stage.

As the issue of oil shortage and air pollution caused by automotive engine emissions become more and more serious day by day, researchers and engineers from all over the world are seeking for alternative fuels of lower pollution and renewable nature. This paper discusses in detail the feasibility of fueling gasoline engines with Butanol-gasoline blends. Besides the production, transportation, storage, physical and chemical properties of Butanol-gasoline blends, the combustion characteristics were analyzed as well. As the result Butanol was considered an excellent alternative fuel for gasoline engines, with many unique advantages superior to Natural Gas, LPG, Carbinol and Ethanol, the latter are widely studied at present time. In order to validate the above conclusions in engine application, engine dyno tests were conducted for a gasoline engine fueled with different concentrations of Butanol blend ranging from 10% to up to 35%.

In this paper the experiments of hydraulic free piston diesel engine is described. The experimental data were obtained from measurement instruments on the free piston diesel engine that has been developed by Beijing Institute of Technology [ 1 ]. This article discusses the influences of compression pressure, injection timing, and combustion process to the free piston diesel engine principle. The compression process experiment shows that the piston velocity, the compression ratio can be controlled by adjusting the compression pressure. With the increasing of the compression pressure, there is a growing a compression ratio and piston velocity. The study on injection timing shows that the injection timing impacts the cylinder pressure peak value and the pressure peak arrival time. The combustion process is quite different from the crankshaft engine because of the unique piston movement characteristics of the hydraulic free piston engine.

This paper introduces a vehicle model in CarSim, and replaces a portion of its standard suspension system with an HIS model built in an external software to implement co-simulations. The maneuver we employ to characterize the HIS vehicle is a constant radius method, i.e. observing the vehicle’s steering wheel angle by fixing its cornering radius and gradually increasing its longitudinal speed. The principles of the influence of HIS systems on cornering mainly focus on two factors: lateral load transfer and roll steer effect. The concept of the front lateral load transfer occupancy ratio (FLTOR) is proposed to evaluate the proportions of lateral load transfer at front and rear axles. The relationship between toe and suspension compression is dismissed firstly to demonstrate the effects of lateral load transfer and then introduced to illustrate the effects of roll motion on cornering.

Along with the booming expansion of private car preservation, many Chinese cities are now struggling with hazy weather and ground-level ozone contamination. Although central government has stepped up efforts to purify skies above China, counter-strategies to curb ground-level ozone is comparatively weak. By using maximum incremental reactivity (MIR) method, this paper estimated the ozone forming potential for twenty-five Euro-3 to Euro-5 passenger cars burning conventional gasoline, methanol-gasoline, ethanol-gasoline, neat methanol and compressed natural gas (CNG). The results showed that, for all the fuel tested, VOC/NOx ratios and SR values decreased with the upgrading of emission standard. Except for Euro-3 M100 and Euro-4 M85, SR values for alternative fuel were to different degrees smaller than those for gasoline. When the emission standard was shifted from Euro-4 to Euro-5, OFP values estimated for gasoline vehicle decreased.

In this paper, a new method for the driving of the hydraulic free piston engine (HFPE) is proposed. Hydraulic differential drive achieves the compression stroke automatically rather than special recovery system, which has a great influence on the engine dynamic performance. The purpose of this paper is to solve the key operation and control problems for HFPE to commix fuel with air. HFPE adopts two-stroke loop-scavenging and semi-direct injection. The semi-direct injection nozzle is located in the liner wall inside the main intake port, with the axes oriented towards the piston at the Bottom Dead Center (BDC). Different scavenging pressures and injection angles result in different impacts on the mixture of fuel and air in the cylinder. This study analyzes the changes of the combustion heat release rate by simulation.

Natural gas is a promising alternative fuel for internal combustion engines due to its rich reserves and low price, as well as good physical and chemical properties. Its low carbon structure and high octane number are beneficial for CO2 reduction and knock mitigation, respectively. Diesel and natural gas dual fuel combustion is a viable pathway to utilize natural gas in diesel engines. To achieve high efficiency and low emission combustion in a practical diesel engine over a wide range of operating conditions, understanding the performance responses to engine system parameter variations is needed. The controllability of two combustion strategies, diesel pilot ignition (DPI) and single injection reactivity controlled compression ignition (RCCI), were evaluated using the multi-dimension CFD simulation in this paper.

The electronic unit pump system, which is widely applied to the heavy-duty diesel engine, belongs to the pulsating high-pressure fuel injection system, and the fuel pressure fluctuations have an essential influence on the spray and combustion in the internal combustion engine. Besides, pressure fluctuations are always aroused by the motion of actuators, such as the injector or other control valves, so it is also an advantage for fault diagnosis and feedback control to ascertain the relationship between the pressure fluctuation and the motion of the actuator. In this study, experiments and 1D-simulation were carried on to investigate the fuel pressure fluctuation characteristics and their correlations with the transient motion of the needle valve in the injector.

The diesel low temperature combustion (LTC) can keep high efficiency and produce low emission. Which has been widely studied at home and abroad in recent years. The combustion control parameters, such as injection pressure, injection timing, intake oxygen concentration, intake pressure, intake temperature and so on, have an important influence on the combustion and emission of diesel LTC. Therefore, to realize different combustion modes and combustion mode switch of diesel engine, it is necessary to accurately control the injection parameters and intake parameters of diesel engine. In this work, experimental study has been carried out to analyze the effect of intake oxygen concentration, intake pressure and intake temperature in combustion and emission characteristics of diesel LTC, such as in-cylinder pressure, temperature, heat release rate, NOx and soot emission.