Heat transfer and stress fields in the inlet and exhaust valves of a semi-adiabatic diesel engine

Abstract

Numerical calculations based on finite difference approximations are carried out to calculate the temperature and thermal stress fields in a semi-adiabatic diesel engine inlet and exhaust valves. The valve plate has been coated by a 2 mm thin layer of oxide-based ceramic insulating material. A detailed analysis has been given for estimating the boundary conditions of the inlet and exhaust valves. The isothermic distribution, heat flow rates to the cooling media and the resulting thermal stresses in the valve bodies for three different engine loadings have been depicted for both cases with and without insulation coating. The results indicate a 16% reduction in heat loss through valves by use of an insulation coating on the valve plate. © 1990.