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The objective of the development of composite pistons is to meet an explosive increase in a worldwide energy demand and to cut down overall product cost. This paper present the design features and the field testing results of the composite piston that requires high durability and wear resistance due to high power output over Pmax of 210-220 bar. The forged steel crown and the nodular cast iron skirt were optimized using the advanced CAE technique. The parametric study of shaking-cooled oil gallery and passage was done in order to assure the optimum ring performance and prevent hot corrosion. The cooling performance was verified through visual inspection and the temperature measurement. Reliability for fastening influences the maintenance cost, and so we were trying to get rid of probability of bolt loosening using statistical techniques like hypothesis testing, etc.

The two-dimensional conservation equations of mass, momentum and energy are solved numerically in order to investigate the thermo-fluid phenomena in the louvered fin array. The governing equations are expressed in the generalized coordinates to consider the complex geometry of louvered fin array. The numerical solutions give the detail distribution of velocity and temperature fields from the inlet to the outlet in the louvered fin array. The pressure drop, flow efficiency and heat transfer rate are calculated as a function of Reynolds number in order to know the optimal design condition with larger heat transfer rate under smaller pressure drop.

The fully developed turbulent momentum and heat transfer induced by three-dimensional roughness elements on the inner wall surface in a dimpled tube is studied analytically based on standard k- ε turbulence model with a Navier-Stokes equation solver. Experimental investigations are also carried out to obtain pressure drop characteristics and to verify the numerical results of the fluid flow. The calculated pressure fields exactly predict the friction factor relation obtained from experiment at high Reynolds number cases, ReD > 4,000. The complex velocity distribution taken from analysis also reasonably well agree with experiment. For the range of present Reynolds number, 2,000 < ReD < 10,000, the numerical analysis demonstrates that the heat transfer enhancement decreases with increasing Reynolds number.