An approach for the thermal analysis of internal combustion engines' exhaust valves

Intake and exhaust valves are important components of internal combustion engines, which are used to control the inflow and outflow of gases. Such valves are subject to thermal loading due to high temperature and pressure inside the cylinder that must tolerate the limit of material temperature for a sustainable and optimal operation. The present study constitutes a contribution to predict the temperature maps of intake and exhaust valves considering the real conditions of an engine operation. An adequate subdivision of the valve is used to better assess the effect of each part of the cylinder head. Therefore, the instantaneous heat transfer coefficient and adiabatic wall temperature for each subdivision are evaluated during the four-stroke of an engine. The average values of these parameters are calculated and introduced as boundary conditions in a finite element model implemented in the commercial code Ansys-CFX. To facilitate the simulations runs of the proposed model, APDL (ANSYS Parametric Design Language) code is developed to extract the thermal map. As an application, this methodology is used to highlight the temperature maps and to show the region of extreme temperature and heat flux in the aim of avoiding any damage.