Performance of Various Hybrid RANS-LES Turbulence Models in an Aerodynamics CFD Simulation of a Simple Pickup Truck Shape

Aerodynamics;CFD;Automotive;Truck;Turbulence;Detached eddy simulation;DES;Vortex;RANS;LES;Automotive Engineering;Mechanical Engineering, College of Engineering & Computer Science

Smolarek, KyleSengupta, Subrata ;

University of Michigan

关键词: Aerodynamics;    CFD;    Automotive;    Truck;    Turbulence;    Detached eddy simulation;    DES;    Vortex;    RANS;    LES;    Automotive Engineering;    Mechanical Engineering, College of Engineering & Computer Science;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/148802/thesis%20%283%29.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

The top three best-selling vehicles in the United States are pickup trucks, therefore their unique aerodynamics are of considerable industrial interest. Hybrid RANS-LES turbulence models are popular in automotive aerodynamics CFD. Papers have examined their performance on simplified car shapes, but none have done so for a pickup truck shape.Three hybrid RANS-LES turbulence models—detached eddy simulation (DES), delayed detached eddy simulation (DDES), and improved delayed detached eddy simulation (IDDES)—were examined in incompressible, transient CFD on a simplified pickup truck shape using OpenFOAM. These models were also benchmarked against Spalart-Allmaras and k-ω SST steady RANS models.The hybrid RANS-LES turbulence models differed in values of drag and lift coefficients by up to 0.002 and 0.014, and predicted on average 0.040 and 0.078 higher than the steady RANS models, respectively. The flow fields of the hybrid RANS-LES models were largely similar to each other, but differed from the RANS results downstream of the front fascia and particularly in highly-detached regions, where they predicted earlier vortex bursting.Wind tunnel test data and flow visualization are required to confirm the results predicted by the hybrid RANS-LES models.