摘要
Direct numerical simulation was carried out to investigate the correlation between the momentum and passive scalar transfer in a turbulent channel flow with Re_(τ)=u_(τ)δ/ν=180 and Pr=0.71,where u_(τ)is the friction velocity,δis the channel half width,andνis the kinematic viscosity.The one-point and two-point energy transfer and the corresponding scalar transfer are of particular interest.There is a significant positive correlation between the one-point energy and scalar transfer,particularly near the wall,and the correlation between the two production terms is always larger than that between the other terms.By resorting to the Karman-Howarth-Monin-Hill equation and the scale-by-scale scalar transfer budget equation,we explored the two-point energy and scalar transfer at two different vertical locations(i.e.,one location close to the wall y^(+)=10 and the other location slightly away from the wall y^(+)=60).An inverse interscale transfer phenomenon of the energy and scalar is observed in the spanwise direction at y^(+)=10,which is caused by the corresponding streak stretching,whereas along the streamwise and the vertical directions a forward interscale energy and scalar transfer phenomenon is observed.The physical mechanisms(e.g.,production,dissipation,and viscous diffusion terms)contributing to the two-point energy transfer closely resemble those in the two-point scalar transfer.The intrinsic correlation between both the two-point energy and scalar transfer can find its roots in the similarity between the momentum and scalar streaks.
对雷诺数Re_(τ)=u_(τ)δ/ν=180(u_(τ)为摩擦速度,δ为槽道半宽,ν为运动黏度)及普朗特数Pr=0.71的槽道湍流开展直接数值以研究槽道湍流中动量和被动标量的输运特性及两者间的相关性.研究结果表明单点能量和标量输运之间存在明显的正相关性,并且生产项之间的相关性总是大于其他项之间的相关性.通过计算Karman-Howarth-Monin-Hill方程和尺度间标量输运方程,研究了法向方向两个距离壁面不同位置处两点间能量和标量输运特性(靠近壁面的位置y^(+)=10,另一个远离壁面的位置y^(+)=60).在y^(+)=10处,在展向方向观察到由动量条带及标量条带拉伸引起的能量和标量的反向传递现象,而在流向和垂直方向观察到尺度间正向能量和标量传递现象.两点间能量输运的物理机制(例如,能量产生、耗散和黏性扩散)与两点间标量输运的物理机制非常相似.能量及标量输运机制的相关性与动量条带和标量条带之间的相似性密不可分.This is a preview of subscription content,access via your institution.
作者
Ahui Tian
Feng Liu
Yi Zhou
田阿慧;刘锋;周毅(School of Energy and Power Engineering,Nanjing University of Science and Technology,Nanjing,210094,China;School of Energy and Power Engineering,North University of China,Taiyuan,030051,China)
基金
the National Natural Science Foundation of China(Grant Nos.91952105,11802133 and 12002318)
the Six Talent Peaks Project in Jiangsu Province(Grant No.2019-SZCY-005)
the Fundamental Research Funds for Central University(Grant No.30918011325).
