抄録
LDV (Laser Doppler Velocimetry) measurement has been made in the high Reynolds number (1010≦Re_τ≦20700) turbulent pipe flow to clarify its velocity properties. The accuracy of the mean velocity in LDV measurement was checked by a comparison between the integration of the mean velocity profile and the actual flow rate measured by a weighting system in AIST (Advanced Industrial Science and Technology), NMIJ (National Metrology Institute of Japan). Mean velocity overlap region satisfies power law and log law, each coefficients are γ = 0.145, C = 8.41, κ = 0.383 and B = 4.38, respectively. Log-linear region in the turbulence intensity profile is observed at Re_τ = 20700, where coefficients are A_1 = 1.44, B_1 = 1.65. This log relation almost collapses mean velocity log region.
