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A novel design of an air-gap insulated piston has been proposed which is expected to give a longer life compared to the existing designs. The new composite piston is made of a crown piece which is fitted to the base of a piston through a gasket by an interference fitting and locked by oval shaped rivets radially. A steady state two dimensional thermal analysis is performed on the piston to predict the temperature distribution, then a thermo-elastic analysis is performed to obtain thermal stress distribution. Further, a pure mechanical stress analysis is performed on the piston. These analyses are performed on a Aluminum single piece piston, as reference and an air-gap insulated Ultra High Strength Steel piston using finite element method. Constant temperatures are assumed at gas, liner and oil boundaries of the piston. Also, film coefficients on the piston boundaries are kept constant.

A novel design of an air-gap insulated piston has been proposed which is expected to give a longer life compared to the past designs and lower heat transfer there by increasing its crown temperature. Also it is light weight. The basic design of the piston, where the crown is separated from the body of the piston through a thick composite gasket. The crown and the piston base are fitted together by an interference fitting and locked by oval shaped rivets. A steady state two dimensional thermal analysis is done on the piston for the following five cases using FEM: Aluminum piston single piece as reference, aluminum crown with thick composite gasket and air-gap with aluminum base, composite crown and air-gap with aluminum base, all composite piston without air-gap and all composite with air-gap. Constant temperatures are assumed at gas, liner and oil boundaries of the piston. Also the film coefficients on the piston boundaries are kept constant for all the cases.