Author(s): N. Srinivas, M. Vinoth, P. Gopal, T. Senthilkumar

Abstract: In order to measure the aerodynamic drag produced, a 1/10th scale model truck, a small scale model (length 1710 mm) of General Motor SUV was built and tested in the wind tunnel for expected wind conditions and road clearance. Two passive devices, rear screen which is plate behind the car and rear fairing where the end of the car is aerodynamically extended, were incorporated in the model and tested in the wind tunnel for different wind conditions. The conclusion is that rear screen could reduce drag up to 6.5% and rear fairing can reduce the drag by 26%. There were additional tests for front edging and rear vortex generators. For trucks, the results show that these external attachments (fairing and covering) have notable impact on aerodynamic drag as they can reduce up to around 26% aerodynamic drag over the baseline model depending on cross wind effects. The full-skirting (using the front fairing, side skirting and gap filling) has maximum impact whereas only front fairing has minimum impact on aerodynamic drag reduction. The results for drag reduction were mixed. It should be noted that there are aesthetic and practical considerations that may allow only partial implementation of these or any drag reduction options.