Vahid sarafrazi - MSc Student, Railway Engineering Department, Iran University of science and Technology
Mohammad reza talaee - Faculty of Railway Engineering Department, Iran University of science and Technology

The heat contact between the exhaust valve and its basement has become a problem well discussed these recentyears. In this research we modeled and obtained the temperature profiles of the exhaust valve of a Chinese diesellocomotive engine 12V180 with periodic boundary conditions. The innovation in this paper, are the periodicboundary conditions, which help us in the analysis of the combustion and radiation of the valve’s stem, then weconfronted the results with the steady boundary conditions which showed a difference of 2%, and if we use a lowquality fuel (which produces more fumes) in the periodic state, the temperature and consequently the thermalstresses of the valve rises and as a result its lifespan will decrease considerably.

convection, radiation, exhaust valve, temperature profile, periodic boundary condition