CAE Cooling Module Noise and Vibration Prediction Methodology and Challenges 2020-01-1262
In NVH domain, cooling module is an important subsystem in ground vehicles. Recently, with the development of small high output turbocharged internal combustion (IC) engines, cooling module noise and vibration has become more challenging. Furthermore, with plug-in hybrid electric vehicle (PHEV), in some cases the cooling fan could be operational while the IC engine is not running. This poses a significant challenge for cabin noise enhancement. Small turbocharged IC engines typically require higher cooling capacity resulting in larger fan size designs with higher speed. Accurate prediction of the imbalance loads generated by cooling fan and loads transferred to the body are critical for NVH performance of the vehicle. If NVH risk of cooling module operation is not well quantified and addressed early in the program, attempts to find solutions in post launch stage could be very expensive and not as effective. In this paper the static imbalance of the fan and motor assembly was studied and influence of couple imbalance was investigated. The results of static imbalance loading, coupled imbalance loading and combination of both imbalance loadings were compared to measurement data. Furthermore, the bushings of the cooling module, which are typically made of hyper-elastic materials, result in significant frequency dependent behavior in the bushing stiffness rates. The influence of modeling the bushings with constant stiffness value was studied in great details and in contrast, frequency dependent rates for bushings were used in modeling to quantify the effect of two different models. The noise and vibration CAE results were compared to measurement data and conclusion and recommendations were made based on best correlation.
Ahmad ABBAS, Wael Elwali, Syed Haider, Suneel Dsouza, Michael Sanderson, Yoginder Segan