Improvement of Baldwin–Lomax turbulence model for supersonic complex flows
Improvement of Baldwin–Lomax turbulence model for supersonic complex flows
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DOI：
10.1016/j.cja.2013.04.047
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发表时间：
2013-06
影响因子：
5.7
通讯作者：
R. Zhao;Chao Yan;Jian Yu;Xinliang Li
中科院分区：
文献类型：
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作者：
R. Zhao;Chao Yan;Jian Yu;Xinliang Li
熵表示能量的耗散率。通过对超声速压缩斜板流动的直接数值模拟，发现无论是在附连区还是分离区，熵值沿壁面法线方向沿着单调递减。基于这一特点，本文提出了一种新的Baldwin-Lomax湍流模型（BL-熵）。选取了原Baldwin-Lomax模型不能得到收敛解的超声速压缩斜坡和空腔斜坡流场来评价该模型的性能。采用Spalart-Allmaras单方程模型和Wilcox k-ω双方程模型计算结果与实验数据和DNS数据进行了比较。结果表明，BL-熵可以克服原来版本的本质缺陷，提供了一个更有物理意义的长度尺度的复杂流动。此外，该方法简单、计算效率高、通用性强，适用于其它与超声速边界层有关的模型。
Entropy represents the dissipation rate of energy. Through direct numerical simulation (DNS) of supersonic compression ramp flow, we find the value of entropy is monotonously decreasing along the wall-normal direction no matter in the attached or the separated region. Based on this feature, a new version of Baldwin–Lomax turbulence model (BL-entropy) is proposed in this paper. The supersonic compression ramp and cavity-ramp flows in which the original Baldwin–Lomax model fails to get convergent solutions are chosen to evaluate the performance of this model. Results from one-equation Spalart–Allmaras model (SA) and two-equation Wilcox k–ω model are also included to compare with available experimental and DNS data. It is shown that BL-entropy could conquer the essential deficiency of the original version by providing a more physically meaningful length scale in the complex flows. Moreover, this method is simple, computationally efficient and general, making it applicable to other models related with the supersonic boundary layer.