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In this paper, a quasi-dimensional multi-zone spray combustion model is developed to simulate the combustion and emission of direct injection engine fueled with dimethyl ether (DME). The analysis of the spray mixing process is based on a quasi-dimensional gas jet model which consists of integral continuity and momentum equations. The heterogeneous field of temperature and temporal distribution histories of fuel in the combustion chamber is considered by dividing the chamber into n-zones. The jet mixing models are used to determine the amount of fuel and entrained air in each zone available for combustion. The mass, energy and state equations are applied in each zone and the combustion process is controlled by chemical reactions which are calculated by adopting CHEMKIN code. The CHEMKIN libraries have been used to formulate a stiff chemical kinetic solver suitable for integration within the engine cycle simulation.

Transient heat transfer computer program of the coupling 3-D moving piston assembly-lubricant film-liner system is successfully developed for predicting the distribution of temperatures in the component system, in which the finite element technology has been employed. The heat transfer relation of the moving piston assembly-lubricant film-liner has been established and 3-D discrete model of the system is obtained with the hypothesis of thinking the lubricant film as 1-D heat resistance. The discrete models of single component are assembled into the whole coupling model with the coupling theory. Some appropriate ways have been employed to deal with the moving arrays in the stiffness matrix because of the moving boundary conditions. The software has been employed to analyze a gasoline engine.

In this paper, a detailed three dimensional (3D) flexible ring tire model is first proposed which includes a rigid rim with thickness, different layers of discretized belt points and a number of massless tread blocks attached on the belt. The parameters of the proposed 3D tire model can be divided into in-plane parameters and out-of-plane parameters. In this paper, the relationship of the in-plane parameters between the 3D tire model and the 2D tire model is determined according to the connections among the tire components. Based on the determined relationship, it is shown that the 3D tire model can produce almost the same prediction results as the 2D tire model for the in-plane tire behaviors.

Analysis of pressure transients in brake system is very important for calculating brake force development, especially for vehicles mounted on ABS (Antilock braking system). This paper introduces an analytical dynamic model of the air-over-hydraulic (AOH) brake system mounted on heavy-duty off-highway vehicle (HOV). The paper relies on physical arguments to develop the mathematic models for the brake system components. And then a generalized AOH brake system, based on the systems analysis level for the components, is formulated in detail. The foundation drum brake is presented with a novel modeling method for the interaction with the apply system. And the pipeline hysteresis and fluid fluctuation of the brake system are well researched. Experiments are preformed on a bench setup and a real vehicle of the AOH brake system and the experimental data is compared with the simulation results. Preliminary analysis shows that the simulation tracks the data closely.

Construction vehicles own some inherent characteristics, such as low velocity, high power and following heavy heat flux et al. Aiming at decreasing flow resistance and managing airflow, a 39 ton single drum road roller from one of the biggest manufactures in China was employed as a research target to seek out the effect of air flow resistance on the performance of its heat dissipation system. For a start, a simplified 3D model of the road roller in a virtual wind tunnel was established with a commercial software, which was pre-processed in Gambit later. The radiators were set with heat exchanger boundary condition based on the analysis on the air-side elementary unit, as for the cooling fan, the experimental results in the wind tunnel were transformed into the corresponding boundary condition.