抄録
In order to obtain the exact universal Karman constant in an equation of a mean velocity profile based on log law, the friction factor for a fully developed pipe flow is examined in high Reynolds number up to Re_D=1.8×10^7 and with high accuracy using the High Reynolds number actual flow facility "Hi-Reff". Using inner scale variables estimated by the present friction factor, the velocity profile measured by LDV in the same measurement configuration for the friction factor is normalized in order to observe the consistency of the Karman constants between both the measurements. The Karman constant is estimated to be 0.385 by the friction factor which is almost consist with the result by the velocity profile for Re_D>3.0×10^5.
