Large Eddy Simulation of the Flow-Field around a Full-Scale Heavy-Duty Truck

Abstract

In this paper, Large Eddy Simulations (LES) of flow field around two different full-scale heavy-duty truck with air deflector and without an air deflector model are presented. The full-scale truck model is considered which contains a number of details such as bumpers, underbody, tractor chassis, wheels and axles. The numerical simulations have been conducted with two virtual wind tunnels at different yaw angle at 0°, 5° and 10°. The models are placed at different yawing angles in the virtual wind tunnels with a blockage ratio of about 10%, which is same as the experimental wind tunnel. To compare the corrected experimental results with the ideal case, other simulations are also conducted with a larger cross section at the blockage ratio of about 1%. A detailed survey of both instantaneous and timeaveraged flow is presented. The steady state simulations with tetrahedral meshes predict the drag coefficient (Cd) accurately within 3.3%, 4.5% and 3.3% of with air deflector model and 1.3%, 4.1% and 7% of without an air deflector model to corresponding experimental values at 0o, 5o and 10o yaw cases, respectively. It is observed that aerodynamic coefficients such as drag coefficient (Cd), side force coefficient (Cs) and lift force coefficient (Cl) depend on yaw angles and as well as vehicle geometry.