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Technical Paper

An Elementary Simulation of Vibration Isolation Characteristics of Hydraulically Damped Rubber Mount of Car Engine

2001-04-30
2001-01-1453
Hydraulically damped rubber engine mounts (HDM) are an effective means of providing sufficient isolation from engine vibration while also providing significant damping to control the rigid body motions of the engine during normal driving conditions. This results in a system which exhibits a high degree of non-linearity in terms of both frequency and amplitude. The numerical simulation of vibration isolation characteristics of HDM is difficult due to the fluid-structure interaction between the main supporting rubber and fluid in chambers, the nonlinear material properties, the large deformation of rubber parts, structure contact problems among the inner parts, and the turbulent flow in the inertia track. In this paper an integrated numerical simulation analysis based on structural FEM and a lumped-parameter model of HDM is carried out.
Technical Paper

Simulating Analysis of Methanol Combustion Process and Variations of Cycle to Cycle in Diesel Engine

2001-05-07
2001-01-1985
A zero-dimension combustion model suitable to multi-fuel combustion process has been developed and successfully used in the analysis of methanol combustion process The V2b function is calculated with the Powell Optimized Algorithm. The concerned characteristics include in the variables of zero-dimension model, mean indication pressure, maximum combustion pressure, ignition delay and the correlation coefficient between heat release rate and ignition delay. The heat release rate curves on different conditions are fitted and the statistic analyses of the cyclic variations are conducted.
Technical Paper

Characteristics of HCCI Diesel Combustion Operated with a Hollow Cone Spray

2003-05-19
2003-01-1823
This paper presents two factors for improving the performance and emissions characteristics in HCCI diesel combustion, one is reducing compression ratio and another is changing the injector position. In a previous study, it was shown that HCCI diesel combustion could be realized by utilizing a hollow-cone spray with normal injection pressure. However there remained two major problems of engine instability and increase in BSFC (decrease in brake thermal efficiency). By reducing the compression ratio from 18.8 to 16.8, the engine stability was much improved to the level of conventional diesel combustion and the increase in BSFC became almost half, which was mainly due to the change of combustion phasing. In addition to this, application of 5 mm inside position of the injector realized almost no penalty of BSFC at higher load condition.
Technical Paper

Mathematical Modeling of Vehicle Fuel Cell Power System Thermal Management

2003-03-03
2003-01-1146
A mathematical model of vehicle fuel cell system thermal management has been developed to investigate the effects of various design and operating conditions on the thermal management and to understand the underlying mechanism. The fuel cell stack structure is represented by a lumped thermal mass model, which has the heat transfer and pressure loss characteristics of the fuel cell stack structure. The whole thermal management system is discretized into many volumes, where each flowspit is represented by a single volume, and every pipe is divided into one or more volumes. These volumes are connected by boundaries. The model is solved numerically to analyze thermal management system performance. The effects of coolant flow rates and air flow rates on the system thermal performance, the stack thermal capacity on the transient thermal performance have been investigated in detail.
Technical Paper

Analysis of Characteristic of Microwave Regeneration for Diesel Particulate Filter

1995-09-01
952058
The mathematical model for the microwave regeneration of diesel particulate filter is proposed according to the characteristic of microwave regeneration process. The model is used to calculate the temperature field, distribution of particulate and density field of oxygen in the filter during the process of regeneration with typical ceramic foam particulate fitter data. The parametric study demonstrates how some of the main parameters, such as microwave attenuation constant of the filter, filter particulate loading, the power and distribution of microwave energy and so on, affect the efficiency of regeneration, the maximum filter temperature and regeneration duration. The results show that it is possible to regenerate the diesel particulate filters in certain conditions by using microwave energy.
Technical Paper

The Study of an Optimum Method for Inlet Port Performance in a D.I. Diesel Engine

1995-09-01
952056
A new concept of “synthetic performance coefficient of inlet port” in D.I. diesel engines has been proposed from a viewpoint of efficiency of energy conversion in this paper. It makes the performance of various kinds of inlet ports in D.I. diesel engines compared with each other. Based on the regression analysis of the experimental results, it is found that the synthetic performance coefficient of inlet port has a close linear relation to the engine performance, and it can be used as a criterion to optimize the design of inlet port in D.I. diesel engines.
Technical Paper

Study of the Injection Control Valve in a New Electronic Diesel Fuel System

1998-02-23
980813
At first, the dynamic electromagnetic characteristics of a pulsed solenoid valve is analyzed by experiments. The fast valve response is obtained by material modifications. Then, the intelligent solenoid driving method is discussed. The new techniques of the “active” PWM and the “d2i/dt2” detection are developed for feedback control of the solenoid holding current and the valve closure timing. Finally, the control and diagnosis method for the valve closure duration is investigated. A sensing mechanism utilizing momentary camshaft speed fluctuations of fuel injection pump is presented, which provides the basis for feedback control and diagnosis of the valve closure duration and diesel fuel injection process.
Technical Paper

Development and Application Experience of Diesel Catalytic Converters

1994-09-01
941773
This paper mainly deals with the harmful emission control problem of the diesel engine. Many research works have been carried out on the catalytic conversion of diesel emissions. First, a few kinds of catalyst are prepared, selected by Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA). Three types of catalytic converter are developed. Engine bench tests on these converters loaded with selected catalysts are made. Testing contents are: (1) conversion rate of harmful gases; (2) reduction effect of exhaust smoke; (3) resistant performance of converters and their influences on the engine, etc. Finally, through comparison, the effective catalytic converter is installed on a folklift truck for testing and durability examination. Testing results show that the catalytic converter has higher conversion rate on gaseous emissions, especially for CO and NOx. After two months running, the conversion rates basically keep the original level.
Technical Paper

Studies on Regeneration of Diesel Exhaust Particulate Filters by Microwave Energy

1994-09-01
941774
It is a new idea and beneficial attempt that the microwave heating technology is applied to regenerate the Diesel Exhaust Particulate Filters (DEPF). In this paper, the microwave regenerating mechanism of DEPF is studied and some laws in the process of microwave regeneration are found by experimental and theoretical analyses. Some basic measurements and calculations of microwave characteristic factors of three kinds of selected DEPF and the pure particulate are presented. A Microwave Regenerating Test System (MRTS) is set and the microwave regeneration of DEPF is tested. A mathametical model of two dimensional axi-symmetrical non-steady temperature field is set up which is suitable for microwave regenerating process of ceramic foam filters. The numerical calculation and practical analyses are stated. It is proved by these studies that the particulate in DEPF is selectively heated by microwave energy and moreover the microwave energy is less absorbed by the pure ceramic filters.
Technical Paper

The Laser Interfero-Holographic and Tomographic Analysis of Concentration and Temperature Distribution of a Three Dimensional Transient Diesel Spray

1994-09-01
941756
This paper provides a new measuring technique to obtain the concentration and temperature field of a unsymmetrical three dimensional transient diesel spray by the laser interfero-holographic and tomographic analysis. The theory to get the concentration and temperature distribution of a spray by laser technique is stated in detail. The experimental installation and optical system are given concretely. Finally, the test results are analysed satisfactorily.
Technical Paper

The Investigation of Calculation Methods for Optimization of the Performance of the Diesel Engine

1993-03-01
930606
Taking a specific diesel engine as a calculation example, three kinds of ptimized calculation methods are studied in detail for the optimization of the performance of Diesel Engine cycle and the following conclusions are drawn: Sequential Linear Programming (S.L.P) suits for the rough optimized calculation of the performance of Diesel Engine cycle. Sequential Unconstrained Minimization Technique (S.U.M.T) suits for the precise optimized calculation of the performance of Diesel Engine cycle with less variables. Orthognal Network Optimization Method (O.N.O.M) has a wide adaptability, but calculating time is longer, it suits for the precise optimized calculation of the performance of Diesel Engine cycle with more variables.
Technical Paper

Experimental Study on Characteristics of Conical Spray and Combustion for Medium Speed D.I. Diesel Engine

1993-03-01
930598
This paper inverstigates a new way of conical spray for medium speed D. I. diesel engine, with which three different construction injectors were used. The feature of conical spray and fuel-air mixture formation were observed by means of schlieren photograph technique. The main result is that the cone top angle of conical injector has influence on formation of fuel-air mixture and performance of engine. The results of test on a single-cylinder engine show the premixed combustion phase was possessed of a large proportions of the whole combustion period, which was become a leading feature. The increasing interest in study of diesel engine combustion is caused by achieving even more stringent emission standards and greatly improving the fuel economy. From present status of this research the traditional combustion system which with orifice nozzel has already exposed some inherent drawbacks.
Technical Paper

Premix Film Type Compression Ignition Combustion

1992-02-01
920694
This paper investigates the difference between the traditional diffusion combustion and hot premix film type combustion on improvement of compression ignition engine performance in all respects. The first part of this paper mainly describes the heat release, air fuel mixing, swirl flow and squish flow and also film formation on diffusion combustion. The second part of this paper describes the development of hot premix combustion, its feasibility and guiding principles. The main purpose of this part is to demonstrate three main measures which should be taken in carrying out premix film formation combustion. The first means is air flow guide ring. The second is film formation process and the third is fine particles fuel injectors: one is supermultiple holes injector and the second is conical spray fuel injector.
Technical Paper

A Solution for Cylinder Wall Scuffing

1992-02-01
920658
A solution for cylinder wall scuffing is researched. By means of the finite element method, a mathematical model to investigate the temperature field and thermal deformation of the piston is established, which can be used for predicting the cylinder wall scuffing in both the design process of a new diesel engine and the improvement process of the combustion system of an operating diesel engine. The experimental data support the calculated results obtained by using the model. As an application example, the temperature fields and thermal deformations of the piston in the 6E150C diesel engine, which suffers from the cylinder wall scuffing during the period of operation, are analyzed quantitatively by using the mathematical model. After an improved piston with new structure and good cooling system is used in the 6E150C diesel engine, the cylinder wall scuffing no longer occurs.
Technical Paper

Simulations on Special Structure ISG Motor Used for Hybrid Electrical Vehicles Aimed at Active Damping

2017-03-28
2017-01-1123
Engine torque fluctuation is a great threat to vehicle comfort and durability. Former researches tried to solve this problem by introducing active damping system, which means the motor is controlled to produce torque ripple with just the opposite phase to that of the engine. By this means, the torque fluctuation produced by the motor and the engine can be reduced. In this paper, a new method is raised. An attempt is proposed by changing the traditional structure of the motor, making it produce ripple torque by itself instead of controlling the motor. In this way a special used ISG (Integrated Starter Generator) motor for HEV (Hybrid Electrical Vehicles) is made to achieve active damping. In order to study the possibility, a simulation, which focus on the motor instead of the whole system, is developed and series-parallel configuration is used in this simulation. As for the motor that used in this paper, four kinds of motors have been investigated and compared.
Technical Paper

Occupant Injury Response Prediction Prior to Crash Based on Pre-Crash Systems

2017-03-28
2017-01-1471
Occupant restraint systems are developed based on some baseline experiments. While these experiments can only represent small part of various accident modes, the current procedure for utilizing the restraint systems may not provide the optimum protection in the majority of accident modes. This study presents an approach to predict occupant injury responses before the collision happens, so that the occupant restraint system, equipped with a motorized pretensioner, can be adjusted to the optimal parameters aiming at the imminent vehicle-to-vehicle frontal crash. The approach in this study takes advantage of the information from pre-crash systems, such as the time to collision, the relative velocity, the frontal overlap, the size of the vehicle in the front and so on. In this paper, the vehicle containing these pre-crash features will be referred to as ego vehicle. The information acquired and the basic crash test results can be integrated to predict a simplified crash pulse.
Technical Paper

Research on Vehicle Stability Control Strategy Based on Integrated-Electro-Hydraulic Brake System

2017-03-28
2017-01-1565
A vehicle dynamics stability control system based on integrated-electro-hydraulic brake (I-EHB) system with hierarchical control architecture and nonlinear control method is designed to improve the vehicle dynamics stability under extreme conditions in this paper. The I-EHB system is a novel brake-by-wire system, and is suitable to the development demands of intelligent vehicle technology and new energy vehicle technology. Four inlet valves and four outlet valves are added to the layout of a conventional four-channel hydraulic control unit. A permanent-magnet synchronous motor (PMSM) provides a stabilized high-pressure source in the master cylinder, and the four-channel hydraulic control unit ensures that the pressures in each wheel cylinder can be modulated separately at a high precision. Besides, the functions of Anti-lock Braking System, Traction Control System and Regenerative Braking System, Autonomous Emergency Braking can be integrated in this brake-by-wire system.
Technical Paper

Experimental and Numerical Study of the Liquid Film Separation and Atomization at Expanding Corners

2017-03-28
2017-01-0856
The phenomenon of a thin liquid film separation and atomization at expanding corners during the spray/wall interaction is usually encountered in premixed charge compression ignition (PCCI) engines. However, detailed information about the film separation is very limited, especially under high injection pressure conditions. In this study, experimental study was conducted to investigate the effects of injection pressure and impingement distance on the evolutions of the impinging spray and the adhered film at simplified geometries with an expanding corner by employing a high-speed camera. In addition, an improved hybrid film separation and atomization model was developed, which includes the sub-models of film separation criterion, film separation mass ratio, and the film atomization model based on the Rayleigh-Taylor instability theory.
Technical Paper

The Evaporation Characteristics of Cylinder Oil of Low-Speed 2-Stroke Marine Engines

2017-03-28
2017-01-0886
The combustion of cylinder lubricating oil (called as cylinder oil for short) is one of the major sources of PM emissions of low-speed 2-stroke marine diesel engines. For pre-mixed combustion low-speed 2-stroke marine gas engines, the auto-ignition of cylinder oil might result in knock or more hazard abnormal combustion - pre-ignition. Evaporation is a key sub-process of the auto-ignition process of cylinder oil droplets. The evaporation behavior has a profound impact on the auto-ignition and combustion processes of cylinder oil droplets, and a great influence on engine combustion performance and emission characteristics. This paper applied an oil suspending apparatus to investigate the evaporation behavior of cylinder oil droplets and base oil droplets. The effects of ambient temperatures on the evaporation process were measured and analyzed. The results indicate that the evaporation of cylinder oil includes heating, evaporating, pyrolysis, and polymerization.
Technical Paper

Effect of Acetone-Gasoline Blend Ratio on Combustion and Emissions Characteristics in a Spark-Ignition Engine

2017-03-28
2017-01-0870
Due to the increasing consumption of fossil fuels, alternative fuels in internal combustion engines have attracted a lot of attention in recent years. Ethanol is the most common alternative fuel used in spark ignition (SI) engines due to its advantages of biodegradability, positively impacting emissions reduction as well as octane number improvement. Meanwhile, acetone is well-known as one of the industrial waste solvents for synthetic fibers and most plastic materials. In comparison to ethanol, acetone has a number of more desirable properties for being a viable alternative fuel such as its higher energy density, heating value and volatility.
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