壁面せん断応力が零近傍の壁乱流の乱流統計平均量(流体工学,流体機械)  [in Japanese] Turbulence Statistics near the Wall with Almost Zero Shear Stress  [in Japanese]

Turbulence statistics near the wall with almost zero wall shear stress are investigated using DNS data obtained from a series of direct numerical simulations (DNS) of Couette-Poiseuille type turbulent flow. Several significant differences are found in the near wall turbulence statistics between Couette-type and Poiseuille-type flows. It is shown that the Couette-type flow has the different production and redistribution mechanisms of turbulence from those of the Poiseuille-type flow. Further investigations of turbulence structures are carried out by using structure dimensionality and circulicity tensors. Turbulent velocity and vorticity fields near the wall with strong shear stress are two-dimensional and two-component respectively, while those with almost zero shear stress are three-dimensinal and three-component respectively.