Performance of an optimized [formula omitted] turbulence model for flows around bluff bodies

Abstract

The flow over a bluff body is an important phenomena in many engineering applications such as aerodynamic performance, buildings, bridges, and pipelines in cross flow. In this sense, such complex flow dynamics has become a huge challenge for both experimentalists and computational fluid dynamicists. With this in mind, widely-used URANS turbulence models, namely the standard k−ϵ, SST and RSM, are compared with an optimized k−ϵ. This optimized version of the standard k−ϵ model is based on the calibration of the k−ϵ parameters (e.g., Cμ, Cϵ2 and Cϵ1) from a strongly vortical flow. This tunned version was used in 3D jet-in-crossflow simulations and predicted far more accurate results than the standard turbulence models. However, to the authors’ knowledge, a systematic comparison of this calibrated model applied to the prediction of flows around bluff bodies has not yet been conducted. In order to verify the fidelity of the optimized model, we compare the numerical results with wind-tunnel experimental data. In general, the optimized k−ϵ turbulence model was surprisingly predictive for bluff bodies when compared to the other turbulence models.