粗さのある曲り円管の流動抵抗

抄録

Friction coefficients have been measured for turbulent flows through curved circular pipes with rough surfaces. An experiment has been carried out under the conditions of equivalent relative roughness k_e/d=3.59×10^-3∼3.25×10^-2, Reynolds number Re < 7×10⁴ and curvature radius ratios R_c=15, 30 and 45. An approximate expression, which expresses the experimental results well, has been derived using the boundary layer approximation.