チャネル乱流における大規模圧力構造の抽出

抄録

Turbulent flow at high Reynolds number introduces large scale structures in the outer region which affect the turbulent motions. Reynolds number dependence on the pressure fluctuations is studied from Direct Numerical Simulations (DNS) data set at Reynolds number 180, 400, and 1000. The results indicate that the peak of root mean square value (r.m.s) of total, slow, and rapid pressure fluctuations depend on the logarithmic Reynolds number. Probability density function (PDF) for the total pressure shows slice difference between the studied range of Reynolds number. Power spectra are similar for the three pressures close to the wall, and at the center of the channel, rapid pressure shows different behavior in the intermediate and the high wavenumber range. Scale structures associated with total, slow, and rapid pressures introduce variation with the Reynolds number suggesting for more work in the scaling analysis.