A lot of the investigations in automotive aerodynamics are still based on strongly
simplified generic bodies such as the Ahmed Body or the SAE body. To close the
gap between these strongly simplified models and highly complex production cars
the new generic DrivAer body model is introduced by the Institute of Aerodynamics
and Fluid Mechanics, Technische Universitat Munchen (TUM). This current study is
focused on three different DrivAer body models namely Fastback, Estateback, and
Notchback and two different underbody types for each model, smooth and detailed.
Hence, total 6 different models are simulated using open source CFD solver
OpenFOAM at two different ground conditions, with ground and without ground effect
(WGS and WoGS). All the models used in simulations are 2.5 scaled down models
as compared with the actual car dimensions. The vehicle velocity considered for this
numerical study is 40 m/s, Reynolds number is 4.87M and turbulence model used is
k-w-SST. The mesh is generated using SnappyHexMesh (SHM) tool of OpenFOAM
and it is around 11 million volume cells for the smooth underbody and 14 million
volume cells for the detailed underbody. The coefficients of drag (C d) values are
within 0.5% to 12% error band as compared against the experimental values
published by the TUM. The coefficients of pressure (Cp) plots are comparable with
experimental results and also the contribution of individual body part in overall C d
values is obtained in this study. All the simulations are carried out using OpenFOAM
2.1.1 on Tata Consultancy Services (TCS) High Performance Computing facility.
Keywords : DrivAer body, External Aerodynamics, OpenFOAM, SnappyHexMesh,
CFD, HPC, TCS.