中国物理B ›› 2017, Vol. 26 ›› Issue (1): 14703-014703.doi: 10.1088/1674-1056/26/1/014703
• ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS • 上一篇 下一篇
Three-dimensional turbulent flow over cube-obstacles
Hao Lu(卢浩), Wen-Jun Zhao(赵文君), Hui-Qiang Zhang(张会强), Bing Wang(王兵), Xi-Lin Wang(王希麟)
- 1. School of Aerospace Engineering, Tsinghua University, Beijing 100084, China;
2. Faculty of Architecture, The University of Hong Kong, Hong Kong, China
Three-dimensional turbulent flow over cube-obstacles
Hao Lu(卢浩)1, Wen-Jun Zhao(赵文君)2, Hui-Qiang Zhang(张会强)1, Bing Wang(王兵)1, Xi-Lin Wang(王希麟)1
- 1. School of Aerospace Engineering, Tsinghua University, Beijing 100084, China;
2. Faculty of Architecture, The University of Hong Kong, Hong Kong, China
摘要： In order to investigate the influence of surface roughness on turbulent flow and examine the wall-similarity hypothesis of Townsend, three-dimensional numerical study of turbulent channel flow over smooth and cube-rough walls with different roughness height has been carried out by using large eddy simulation (LES) coupled with immersed boundary method (IBM). The effects of surface roughness array on mean and fluctuating velocity profiles, Reynolds shear stress, and typical coherent structures such as quasi-streamwise vortices (QSV) in turbulent channel flow are obtained. The significant influences on turbulent fluctuations and structures are observed in roughness sub-layer (five times of roughness height). However, no dramatic modification of the log-law of the mean flow velocity and turbulence fluctuations can be found by surface cube roughness in the outer layer. Therefore, the results support the wall-similarity hypothesis. Moreover, the von Karman constant decreases with the increase of roughness height in the present simulation results. Besides, the larger size of QSV and more intense ejections are induced by the roughness elements, which is crucial for heat and mass transfer enhancement.
中图分类号: (Turbulent flows)
- 47.27.-i