高レイノルズ数円管流れにおける管摩擦係数と流速分布

Abstract

The mean velocity profile and the friction factor was measured at high Reynolds number using high Reynolds number actual flow facility (Hi-Reff) at NMIJ, AIST. The Reynolds number range of this experiment is from ReD=1.2×104 to 1.8×107. The Karman and additive constants of the mean velocity profile have the Reynolds number dependency for ReD<5.0×105 and they are constant for ReD>5.0×105. The Karman constants obtained from the velocity profile measurement and the friction factor measurement are completely consistent, which is 0.383, for ReD>5.0×105.