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This paper presents four methodologies for modeling gear mesh excitations in simple and compound planetary gear sets. The gear mesh excitations use simplified representations of the gear mesh contact phenomenon so that they can be implemented in a numerically efficient manner. This allows the gear mesh excitations to be included in transmission system-level, multibody dynamic models for the assessment of operating noise and vibration levels. After presenting the four approaches, a description is made regarding how they have been implemented in software. Finally, example models are used to do a comparison between the methods

Noise radiated by engine front cover is estimated using statistical energy analysis approach. Correlations are made with the results obtained using FEM and BEM approaches. Parametric studies are also carried out to assess the regions of applicability of the SEA approach for this class of structures.

It has been found during the transmission level test that oil pan is a major contributor of noise to the overall noise emanating from transmission. Oil pan being thin and having substantial surface area becomes a significant noise source. Keeping this in view it is very important to study the acoustic behavior of the oil pan. Several computational techniques are available to study the noise characteristics of such structures. Indirect techniques that compute normalized velocity distributions on the surface from frequency response analysis give a quick assessment of sound power of the structure but can't give the Sound Pressure Level (SPL) at microphone locations. Technique such as Boundary Element Method (BEM) can calculate the SPL but are computationally intensive as the size of the model increases. Infinite Element techniques overcome these shortcomings from the way they are formulated.