CFD Analysis Around Ahmed Body Using a Laminar Kinetic Energy Based Transition and Turbulence Model

Abstract

Due to numerous reasons, improving the fuel efficiency has become a very important topic for research nowadays. One of the ways to improve fuel efficiency is to reduce the drag forces encountered by moving bodies. For prediction of drag forces, diversified approaches can be undertaken. CFD simulations provide these, but their accuracy is very dependent on the modeling of transition effects in the turbulence model. In the present study, a simple shape (called Ahmed Body) has been investigated using an open-source CFD software called OpenFOAM. Two different classes of turbulence models (namely k − ω SST and k − kL − ω) have been used and the obtained results are validated against experimental data. Efforts have also been made in the present research to analyze the vortices in the wake region of the Ahmed Body using selected visualization techniques such as surface line-integral convolution, Q-criterion, and λ2-criterion.

An Arbitrary Hybrid Turbulence Modeling Approach for Efficient and Accurate Automotive Aerodynamic Analysis and Design Optimization

“…The k-SST model The shear stress transport (SST) k-ω model is a low Reynolds-number two-equation turbulence model [23]. The current model appears to be the combination of k-ω model in the viscous boundary sublayer and k-ε model in the regions that are away from walls.…”

“…The current model appears to be the combination of k-ω model in the viscous boundary sublayer and k-ε model in the regions that are away from walls. The model has two additional transport equations for turbulence kinetic energy, k and specific dissipation rate, ω [23]:…”