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This paper deals with the application of Finite Element Analysis in accelerating the development of an automotive muffler. The essential function of a muffler is to route the exhaust gases from the engine exhaust manifold while reducing the noise and back-pressure. Noise reduction is an emerging concern in the automotive industry, and reduction in back-pressure enhances the fuel economy of the engine. Virtual simulation for back-pressure testing is performed by Computational Fluid Dynamic (CFD) analysis using AcuSolve CFD. Finite Element (FE) model generation of the muffler structure is performed using HyperMesh as the preprocessor. The structural mesh is modeled using 2D shell elements, wherein the internal tubes with fine perforated holes are considered. The CFD fluid meshing is done with tetra elements using AcuConsole as the CFD preprocessor.

Generally three cylinder engines due to less reciprocating masses are said to be more fuel efficient. Nevertheless, NVH problems caused by inherent imbalance forces and couples remain as draw back. NVH refinement levels can be improved by stiffening of the engine structure, material change, optimal design of the crank train, control of cylinder to cylinder pressure variation, etc. The objective of this study is to reduce the radiated noise of diesel engine by 2-3 dB (A) in the frequency range up to 4 kHz. Simulation and test based approach was demonstrated for reducing radiated engine noise. The NVH performance of the baseline engine has been evaluated using CAE simulation tools. Radiated noise from the critical components like oil sump, crank pulley and timing cover has been predicted and the critical modes having severe effect on radiated noise levels of the engine has been identified.