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With the increase of strengthening degree, the parts of vehicle engines are required to bear much heavier mechanical and thermal loads. Great importance is attached to the Low Heat Rejection (LHR) technique to reduce the thermal loads and heat rejection in the field of internal combustion engines. Bearing heavy mechanical and thermal loads, cylinder heads are the most complicated parts and the key point of the LHR technique application in engines. This paper presents the researching work of the LHR cylinder head and its structure. A three-dimensional Finite Elements Analysis (FEA) of the cylinder head was offered and a large amdunt of significant data were obtained to find out the teniperatures field distribution a n d comprehensive stresses field distribution. LHR cylinder heads have greatly reduced the amount of heat rejection. This paper may provide some insights for the LHR cylinder head's designs.

A three-dimensional EHL analysis has been presented to investigate tribological performance of piston ring and cylinder liner contact. The average Reynolds equation and asperity contact approach are applied. For a more realistic simulation, the factors that have effects on the tribological performance of piston ring are considered as many as possible. The equation has been solved cyclically in a fully flooded inlet boundary condition and a flow-continuity Reynolds boundary condition for cavitation outlet zone. The results show that the elastic deformation and cylinder liner shape significantly affect the tribological performance of piston ring. A heat transfer model has been built to evaluate the effect of friction heat on the temperatures of piston ring pack and cylinder liner. The temperature fields can be acquired by the FEM. The results show that the friction heat mainly affects the temperature of region near the top ring groove.

Non-replicated factorial experiment is a kind of specific experiment, which can analyze factorial experiment with no replicates. This property makes it a useful analytical tool to cooperate with engine simulation for the analysis of engine performance. In the article we use this technique to explore the effects of valve timing variable on engine performance in an SI engine simulation. Results drawn from the analysis can help to give us a better understanding of the mechanism of valve timing.

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.

Affecting the normal running and determining the service lives of internal combustion engines, the lubrication and wear of the piston ring and cylinder liner pair are one of the most important area in tribology and studied both by theoretical analysis and experimental investigation by many researchers. In this paper, two-dimensional full numerical analysis is developed for the lubrication analysis of the piston ring based on the flow of lubricant. The forming of the lubricant film and the characteristics of the pressure distributions on the piston ring surface are studied. The detailed effects of many different factors, such as temperature, surface roughness, mixed lubrication and deformation of cylinder liner, are discussed. The calculating results show that the lubrication performance of piston ring significantly depends on those factors. This paper may provide some insights for the analysis of the lubrication performance of piston ring.