Abstract
The purpose of this work is to measure and provide a qualitative and quantitative analysis of the aerodynamic mechanisms connected with the lateral drift of a light van industrial vehicle during the overtaking phase. A dual approach, experimental and analytical, was followed in order to validate CFD analyses (conducted with the STAR-CD code) with the experimental results and provide a qualitative as well as quantitative analysis of the phenomenon. a) Experimental analysis. Two type Daily 35.10 vans were installed in FIATs wind tunnel. The aerodynamic loads were then measured on the vehicles standing alongside in different positions to simulate the overtaking condition with a succession of static positions, obtaining the three forces and the three moments acting on the overtaken vehicle according to the longitudinal, vertical, transverse axes. b) Analytical analysis. The various positions tested in the wind tunnel were reproduced analytically. The data thus obtained, in addition to those taken in the wind tunnel, were the pressure and velocity fields in every area and volume surrounding the vehicles. These data allowed a qualitative assessment and interpretation of the phenomenon, allowing to suggest modifications to reduce its size. The values of the aerodynamic forces obtained in the tunnel were inserted in an Adams model simulating the dynamic behavior of the vehicle on the road, analytically reproducing the drift measured on the road. In conclusion, CFD analysis has provided results that are qualitatively comparable with the experimental ones and has allowed to interpret the aerodynamic phenomena linked to vehicle drift, and to propose improvements.