Detailed CFD Modeling of Engine Cooling Fan Systems Airflow

Requirement for more compact and more efficient fan systems to improve the automotive thermal management has urged Valeo to develop a complete automatic CFD procedure to numerically simulate the fan system. The present study has focused on the description and the validation of the flexible grid template that is meant to simulate the internal flow field within the fan system. This template closely fits in the previously developed rotor-stator parametric grid. The initial small rib reference design has been meshed and four different large rib cases with increasing geometrical difficulties have helped testing this new capability. The simulations have been performed on a medium size grid that has been shown to capture most of the important flow features. The ribs act as centrifugal pumps that drain airflow through the electrical motor. Larger ribs are shown to increase the flow rate through the motor by up to 25% with a marginal increase with swept ribs compared to radial ones.