抄録
Turbulent concentric annular pipe flows with thin inner rods were investigated by means of the direct numerical simulation (DNS). In the inner region, the mean velocity shifts downward from the logarithmic law and the Reynolds stresses decrease monotonously as the radius ratio decreases. We found that the skewness, flatness, two-point correlation and instantaneous field for very small radius ratios are much different from those for large radius ratios.
