Influence of Wheel Wake on Vehicle Aerodynamics: An Eddy-Resolving Simulation Study

A computational study of the vehicle aerodynamics influenced by the wake of the rotating wheel taking into account a detailed rim geometry is presently performed. The car configuration corresponds to a full-scale (1:1) notchback configuration of the well-known ‘DrivAer’ vehicle model, Heft et al. [1]. The objective of the present work is to investigate the performance of some popular turbulence models in conjunction with different methods for handling the wheel rotation – rotating wall velocity, ‘multiple reference frame’ and ‘sliding grid algorithm’. The specific focus hereby is on a near-wall RANS eddy-viscosity model based on elliptic-relaxation, sensitized to resolve fluctuating turbulence by introducing a specifically modeled production term in the scale-supplying equation, motivated by the Scale-Adaptive Simulation approach (SAS, [2]), proposed by Krumbein et al. [3]. All relevant model equations have been implemented in the OpenFOAM® Code, with which all simulations are performed. The results interpretation includes the instantaneous and time-averaged flow properties in terms of the velocity and pressure fields characterizing the underlying flow topology, the integral aerodynamic force coefficients, and finally the POD (Proper Orthogonal Decomposition) analysis, which allows to detect most energetic spatially-independent coherent structures.