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The advent of Eco-Boost technology in gasoline engines creates new challenges that need to be addressed with innovative designs. One of them is flow induced noise caused by flow, entering the turbocharger, at off design operation. At certain vehicle operation conditions, the mass flow rate and pressure ratio are such that compressor wheel generates a broad band frequency noise caused by flow separation from blade surfaces, which is called ‘whoosh’ noise. Flow bench and engine testing can be used to detect flow induced noise, but understanding the fundamental mechanisms of such noise generation is necessary for developing an effective design. This paper describes Computational Aero-Acoustic (CAA) analyses performed to study the effects of inlet condition on the whoosh noise. A 3D Computational Fluid Dynamics (CFD) simulation performed including the entire compressor wheel and volute. The wheel consisted of six main and six splitter blades.

A CAE method has been developed to address engine tonal noise and whine due to the excitation from a gerotor oil pump. The method involves a multidisciplinary approach including CFD, frequency-response structural analysis and acoustic analysis. The results from the application of the method applied to a couple of pumps with different designs are discussed. Engine tonal noise improvement through reduction in the excitation source from the pump and also stiffening the excitation path from the pump to the engine are studied. The effect of component modal alignment with oil pump orders is addressed as well.