An assessment of drag reduction devices for heavy trucks using design of experiments and computational fluid dynamics

Aerodynamic drag, lift, and side forces have a profound influence on fuel efficiency, vehicle speed, stability, acceleration and performance. All of these areas benefit from drag reduction and changing the lift force in favor of the operating conditions. The present study simulates the external flow field around a heavy truck with three prototype add-on drag reduction devices using a computational method. The model and the method are selected to be three dimensional and time-dependent. The Reynolds-averaged Navier Stokes equations are solved using a finite volume method. The Renormalization Group (RNG)ek- model was elected for closure of the turbulent quantities. The run cases were chosen so that the influence of each drag reduction device could be established using a regression model from a Design of Experiments (DOEX) derived test matrix.