DIRECT NUMERICAL SIMULATION OF SPATIALLY DEVELOPING TURBULENT BOUNDARY LAYER FOR SKIN FRICTION DRAG REDUCTION BY WALL SURFACE-HEATING OR COOLING
DIRECT NUMERICAL SIMULATION OF SPATIALLY DEVELOPING TURBULENT BOUNDARY LAYER FOR SKIN FRICTION DRAG REDUCTION BY WALL SURFACE-HEATING OR COOLING
复制标题
DOI：
10.1080/14685248.2012.710750
复制
发表时间：
2012-08
期刊：
影响因子：
--
通讯作者：
Y. Kametani;K. Fukagata
中科院分区：
文献类型：
--
作者：
Y. Kametani;K. Fukagata
本文对具有均匀加热或均匀冷却条件的零压力梯度空间发展湍流边界层进行了直接数值模拟，目的是减少表面摩擦阻力。基于自由流速度U∞、进口99%边界层厚度δ0和运动粘度ν的雷诺数设为3000，普朗特数为0.71。计算域分别在流方向、墙法线方向和展向方向设置为9πδ0×3δ0×πδ0。对壁施加恒定的温度。浮力的理查德森数Ri在−0.1≤Ri≤0.1的范围内变化。DNS结果表明，UC降低了表面摩擦阻力，最大减阻率为65%，而UH则提高了表面摩擦阻力。这一趋势与Iida和Kasagi（1997）、Iida等（2002）研究的通道流和Hattori等（2007）研究的空间发展边界层流的趋势相似。基于单位方程的蒙皮摩擦阻力动力学分解…
Direct numerical simulation (DNS) of zero-pressure-gradient spatially developing turbulent boundary layer with uniform heating (UH) or cooling (UC) is performed aiming at skin friction drag reduction. The Reynolds number based on the free-stream velocity, U ∞, the 99% boundary layer thickness at the inlet, δ0, and the kinematic viscosity, ν, is set to be 3000 and the Prandtl number is 0.71. The computational domain is set to be 9πδ0×3δ0×πδ0 in the streamwise, wall-normal, and spanwise directions, respectively. A constant temperature is imposed on the wall. The Richardson number Ri for the buoyancy is varied in the range of −0.1⩽Ri⩽0.1. The DNS results show that UC reduces skin friction drag with a maximum drag reduction rate of 65%, while UH enhances it. The trend is similar to that in channel flow studied by Iida and Kasagi in 1997 and Iida et al.in 2002 and that in spatially developing boundary layer flow by Hattori et al. in 2007. Dynamical decomposition of skin friction drag using the identity equatio...