Development of a Math-Based Piston Noise Model

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.