Fan Noise Prediction using CFD and its Validation

The latest requirements for automotive cabin comfort require lower sound levels inside the cabin. There are many sources contributing to this noise of which fan is an important one. The blade passage noise of the cooling fan is often unpleasant and it is generally expensive to build and test different prototypes for optimum noise performance. Also, traditional unsteady computational approaches for predicting the fan noise are time and resource consuming and do not fit within the design cycle time. This paper proposes use of a steady state computational technique to predict the fan noise performance which provides for effective design study with optimum resources. The steady state data is used with the wave analogy to predict the overall sound pressure level. First, the computational results were validated with the experimental data for a base case and then parametric study was carried out to have optimum design. The approach is computationally cheaper and can be applied early in the acoustic design of fans.