Simulation of the Noise Radiated From an Operating Diesel Engine

Abstract Numerical methods can be used to compute the vibration of powertrain systems or components and the corresponding radiated noise. Specifically, the finite element method can be utilized in computing the structural vibration[l-3]. The structural response constitutes the boundary conditions for the acoustic analysis. The boundary element method is utilized in computing the radiated noise[4–6]. In order to achieve reliable noise predictions it is important to have accurate information for the structural vibration since it is the source of the noise. In this work a methodology for applying the loads on the structure is presented. It allows to exert as excitation a combination of measured accelerations, and forces or pressures. It is utilized in simulating the noise radiated from a running engine and determining the effects of design changes. Numerical results for the radiated noise are compared to test data for a baseline design. The effect of two structural design modifications on the radiated noise is computed, and conclusions are deducted.