The experimental and numerical research on aerodynamic lift of automobile windshield wiper

Current researches on the aerodynamic lift of automobile windshield wiper are widely focused on the steady numerical calculation of static angle, and the research results of different papers are various, yet no test result can be found to support the simulations. A wind tunnel test is designed and executed to validate and verify the simulation method. Steady aerodynamic lifts of four kinds of wipers with different wind speeds and different rotate angles are measured using multi-point test method. The combination of wind tunnel test and steady numerical calculation helps understanding of lift generation and variation. Furthermore, a new dynamic mesh strategy called the domain-box of dynamic mesh is proposed, the transient aerodynamic lift is simulated and analyzed with User Definition Function method (UDF). The researching result shows that the maximum aerodynamic lift of all four wipers can counteract 68.6% of the precompression, the effect of aerodynamic lift on the stability of wiper cannot be ignored. The lift will achieve its maximum at a certain wind speed and angle, and the magnitude of lift depends on the wind speed of the windward side, the spiral vortex of the leeward and the angle between wind and wiper. Furthermore, the aerodynamic lift is lower than that of steady case when the wipers ascends, and higher when descends.