Numerical study on influence of protrusion heights on Reynolds stress and viscous stress variations in turbulent vortical structures

作     者：Zhiping LI Long HE Jingsai ZHOU Yueren ZUO Yao YIN Peng ZHANG Bo MENG Zhiping LI;Long HE;Jingsai ZHOU;Yueren ZUO;Yao YIN;Peng ZHANG;Bo MENG

作者机构：Research Institute of Aero-EngineBeihang UniversityBeijing 100191China School of Energy and Power EngineeringBeihang UniversityBejing 100191China Institute of AcousticsChinese Academy of SciencesBeijing 100190China College of Aeronautical EngineeringCivil Aviation University of ChinaTianjin 300300China AECC Hunan Aviation Powerplant Research InstituteZhuzhou 412002China 

出 版 物：《Chinese Journal of Aeronautics》 (中国航空学报（英文版）)

年 卷 期：2024年第37卷第9期

页      面：59-71页

核心收录：

学科分类：080103[工学-流体力学] 08[工学] 080104[工学-工程力学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：the National Natural Science Foundation of China(No. 52176032) the Natural Science Foundation of Tianjin Municipal Science and Technology Commission, China(No. 22JCQNJC00050) the National Science and Technology Major Project, China(No.2017-Ⅱ-0005-0016) 

主　　题：Riblet Dragreduction Protrusion height Vortical structure Vortexdiffusivity Reynolds stress Viscous stress 

摘      要：Analysing the influence mechanism of the riblet protrusion height on turbulent drag components is more beneficial in organising the vortical structure over the riblet ***, the Large Eddy Simulation(LES) is used to investigate the vortex structure over the riblet surface with different protrusion heights. Then, the variations of Reynolds stress and viscous shear stress in a turbulent channel are analysed. As a result, the drag reduction rate increases from3.4% when the riblets are completely submerged in the turbulent boundary layer to 7.9% when the protrusion height is 11.2. Further analysis shows that the protrusion height affects the streamwise vortices and the normal diffusivity of spanwise and normal vortices, thus driving the variation of Reynolds stress. Compared with the smooth surface, the vorticity strength and the number of streamwise vortices are weakened near the wall but increase in the logarithmic layer with increased protrusion height. Meanwhile, the normal diffusivity of spanwise vorticity decreases with the increase of protrusion height, and the normal diffusivity of normal vorticity is the smallest when the protrusion height is 11.2. Moreover, the protrusion height affects the velocity gradient of the riblet tip and riblet valley, thus driving the variation of viscous shear stress. With the increase of protrusion height, the velocity gradient of the riblet tip increases dramatically but decreases in the riblet valley.