Performance Analysis of Commercial Vehicle Engine Cooling Fan Based on Fluid-Structure Interaction Method

When the cooling fan of the commercial vehicle engine is working, there is a strong fluid-structure interaction (FSI) between the airflow and the blades. If the effect of this interaction is not considered, significant errors may be caused in the prediction of fan performance. To analyze the effect of FSI on the aerodynamic and structural performance of the cooling fan, calculation models with and without considering FSI were established. The pressure and efficiency of the cooling fan were calculated using three methods:the Multiple Reference Frame (MRF) method, the Sliding Mesh method, and the bidirectional FSI method. These results were then compared with test data. Based on the FSI method, the aerodynamic and structural performance of the fan at different flow rates, rotational speeds and temperatures were calculated, and compared with results if FSI is ignored. The effect of flow rate, rotational speed and temperature on the fan performance was analyzed. The comparison and analysis results show that: (1) The calculation results of the sliding mesh method are generally more accurate than those of the MRF method and the FSI method, with the FSI method being more accurate than the MRF method, especially at high flow points; (2) If fluid-structure interaction is considered, stress and deformation of the blades are smaller compared to the case without FSI; (3) Within the working range, temperature has a significant effect on structural performance but a small effect on aerodynamic performance; (4) Due to the fixed circular shroud at the blade tip, deformation remains minimal, and aerodynamic performance is not significantly affected at operational speeds.