Thermal and Conjugate Heat Transfer Analysis of Exhaust Manifold of Multi-cylinder IC Engine

Abstract

The exhaust manifold of multi cylinder IC engine is kept in between the engine block and the catalytic converter. So the exhaust manifold is exposed to very high temperature and care should be taken at the critical zone during the design stage. At several critical zones of the exhaust manifold, large compressive deformations are generated at elevated temperatures and tensile stresses remain at cold conditions. The thermal analysis will help in estimating the deformations and stress concentrations due to thermal loads. Therefore, the main aim of this study is to perform thermal analysis and conjugate heat flow analysis of an exhaust manifold of a multi-cylinder engine. The 3D model is generated using SolidWorks and analysis is carried out using Ansys workbench. Materials like grey C.I., aluminium nitride, silicon nitride, and stainless steel are used in this analysis. The results of total heat flux, directional heat flux and temperature distribution were compared. Silicon nitride material is suggested to be the suitable material for engine exhaust manifolds based on the material mechanical properties and thermal distribution-related thermal stress developed on the exhaust manifold.