Abstract
Noise and vibration simulation of power units for acoustic optimization is a well accepted task in the engine development process. For design of engine mounts and the analysis of excitation transfer to the vehicle chassis, accurate simulation models for the engine mounts are required. The characteristic of vibration damping mounts depends highly on frequency. On the other hand, due to the non-linear contact behavior between engine components, the forced vibration analysis of power units must be performed in time domain to receive accurate results up to 3 kHz. Therefore a procedure was developed to consider the frequency dependent mounts by using a lumped parameter model, implemented in AVL EXCITE for dynamic and acoustic simulation of power units. The parameters were obtained by identification derived directly from measured engine mount transfer functions. A comparison of engine mount acceleration levels was carried out with experimental data on a 4 cylinder in-line engine. The 1/3 octave acceleration levels up to 1 kHz show a good correlation throughout the engine operating range.