Development of a Transient Thermal Analysis Model for Engine Mounts

Engine mount is one of the temperature sensitive components in the vehicle under-hood. Due to increasing requirements for improved fuel economy, the under-hood thermal management has become very challenging in recent years. In order to study the effects of material thermal degradation on engine mount performance and durability; it is required to estimate the temperature of engine mount rubber during various driving conditions. The effect of temperature on physical properties of natural rubber can then be evaluated and the life of engine mount can be estimated. In this paper, a bench test is conducted where the engine mount is exposed to a step change in the environment around it, and the temperature of the rubber section is recorded at several points till a steady state temperature is reached. A time response curve is generated, from which a time constant is determined. Based on the time constant, an engine mount thermal model is built using a series of first order system response curves. The developed model is compared against measured temperatures from actual vehicle test data. Modeling approach and results discussed in this paper provide guidance for predicting temperature distribution inside the engine mount rubber material under various driving conditions for future vehicle programs to improve the component robustness and durability.