High frequency model describing the noise transfer behaviour of automotive hydraulic engine mounts

Abstract

To further decrease carbon dioxide emissions, efficiency of combustion engines in passenger cars needs to increase. Measures enhancing efficiency in combustion engines significantly increase engine vibrations. In order to provide a high level of comfort and low interior noise levels, isolation properties of engine mount systems have to compensate these increasing excitations. As existing analogous models of hydraulic mounts describe their behaviour only at low frequencies, we elaborate a model describing the isolation properties in a frequency range relevant for dominant engine orders. We deduce this model from parameter variation tests on hydraulic engine mounts using an electrodynamic test bench for characterisation. The parameters in the proposed model represent geometric properties as well as physical properties of springs, masses and dampening effects. Using the elaborated model helps to tune the parameters of engine mounts to the specific demands of different vehicles and to increase isolation properties.