Heat Transfer and Thermal Load Analysis of Exhaust Manifold

With the appearance of high temperature resistance alloy steel and the requirement of light weight for vehicles, more and more exhaust manifolds are made from newly developed alloy steel. The changing of material directly affects the design and manufacturing process. To estimate the thermal load of the tight-coupled exhaust manifold, the joint analysis methods of CFD and FEM are put forward to predict the temperature distribution, thermal stress and deformation. Using Computational Fluid Dynamics (CFD) method, gas temperature and convective heat transfer coefficient, adjoining the inside and outside surfaces of the exhaust manifold, are estimated firstly in this paper. Then these results are mapped to the finite element mesh of exhaust manifold, which are created for the heat transfer analysis. At last, thermal stress and thermal deformation analysis are presented by taking nonlinear material properties into account, which provide some reference to evaluate the cooling capacity and structure design of exhaust manifold.