PANS and DES of a Simplified Heavy-Duty Vehicle. Comparison and an Active Flow Control Application

Abstract

This work presents two main purposes: one is to see how the partially-averaged Navier-stokes (PANS) method performs against the detached eddy simulation (DES) method for different grid refinement levels, when applied to the study of the external aerodynamics of a generic heavy-duty vehicle, and the other is to study the application of Active Flow Control (AFC) on the trailer front pillars of a generic heavy-duty vehicle, on a dynamic oscillating configuration, using PANS. For the first part, a cross analysis of the flow physics around the generic heavyduty vehicle and a comparison of the time-averaged and the instantaneous flow structures, force coefficients and aerodynamic forces of the results obtained using DES and PANS with three grids of different level of refinement, is performed. The results show that both PANS and DES simulations capture the same main flow features and produce similar trends, which are in accordance with published works. The DES shows more robustness, as its results using the three different meshes are more similar than in PANS, and it handles the coarser mesh better, since the PANS results with the coarse mesh show a significant deviation from the ones using the more refined meshes. For the second part, the heavy-duty model is simulated to have a dynamic oscillation of the yaw angle between −10 < < 10 with a non-dimensional frequency St = fW/Uinf = 0.1, with and without the actuation of AFC in the trailer front pillars. Overall, the actuation is not effective and even shows to be disadvantageous.