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With its advantages on cost and performance, the integrated exhaust manifold (casting with the turbine) is being used on more vehicles by auto makers. Generally, when compared with the divided exhaust manifold, the integrated exhaust manifold stands for higher vibratory excitation from gas dynamics. In this paper, the gas dynamics excitation has been computed through the GD (gas dynamics) software GT-Power which calculates the exhaust pipe surface pressure, and CFD code Star-CCM+ which calculates the turbine blade force. And the response of manifold has been solved under this excitation. On the other hand, the mechanical excitation has been computed through the MBD (multi-body dynamics) platform AVL-Excite-PU, and the responses under the gas excitation plus the mechanical load have been studied in order to analyze the effects of the fluid excitation on an integrated manifold.

In engine radiated noise analysis, the conventional boundary element method (BEM) is unsuitable for conducting large-scale acoustic simulations because of low calculation efficiency. The Fast Multipole boundary element method (FMBEM), although greatly improved calculation efficiency for large-scale acoustic simulations, has the problem of low efficiency at the low frequency region and low accuracy at the high frequency region. Those methods cannot meet the requirements of design engineers to get the results in a couple of days. In order to solve the powertrain radiated noise problems accurately and efficiently, some simplified methods and scripts were developed in big-three auto makers and suppliers, such as DIRA. Those scripts are very fast and can meet the timing requirement, but generally, without clear physical meaning.