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A new math-based piston noise model is proposed. It is based on a EHD (elastohydrodynamic) piston lubrication and secondary dynamic analysis. The model predicts the force on the bore wall as a function of time, which is then transformed to the frequency domain. The dynamic calculations of the model were validated against a closed form solution for a simple 1-D model. The model was applied to a production V8 engine. Predictions of the model compared well with block acceleration measurements for the same engine both in relative magnitude and frequencies. Effects of changing clearance and oil supply were also investigated using the model.

An array of engine bearing analysis methods has been developed at General Motors over the years. All of these analyses consider wedge and squeeze effects, finite-length bearing, variation of load with crank angle, and cavitation effects. The simplest among them utilizes the so-called mobility method for solving the governing Reynolds equation. Others include finite-element solution for bearings with arbitrary geometry and grooving, finite-element solution for elastohydrodynamic lubrication, mass-conserving finite-volume solution, non-Newtonian lubricant analysis, and thermohydrodynamic analysis. This paper reviews these methods, describes when and how these methods are used, compares results and describes some applications.