Optimization of Radiator Fan for NVH Improvement

With the development of automobile industry, customer awareness about NVH (Noise, Vibration and Harshness) levels in passenger vehicles and demands for improving the riding comfort has increased. This has prompted automobile OEMs to address these parameters in design stage by investing resources in NVH research and development for all components. Better NVH of Radiator Fan Module (RFM) is one of the parameters which contributes to cabin comfort. The basic objective of RFM is to meet engine heat rejection requirements with optimized heat transfer and air flow while maintaining NVH within acceptable levels. The rotating fan (generally driven by an electric motor), if not balanced properly, can be a major source of vibration in the RFM. The vibration generated thus, can be felt by customer through the vehicle body. This paper discusses about methods used to measure body vibration, to identify the source component of vibration (RFM in this case) and to correlate the body vibration with component level vibration. The test results show a good relationship between RFM vibration and vehicle vibration.