2025 年 30 巻 2 号 p. 87-95
The epoxy resin coating used as a coating for the inner surface of pipes was verified by plotting the results of hydraulic experiments as a line between the Reynolds number Re and the friction loss coefficient λ in a Moody diagram. In the evaluation of the relationship between Re and λ, constants such as the Kalman constant were made variable by the Prandtl-Kalman equation based on the mean flow logarithm law. Using a method that satisfies the log law and the Prandtl-Kalman equation, Kalman's ordinary and other constants are determined. The friction loss coefficients obtained from hydraulic experiments are in good agreement with the reproduced calculations using the set constants, suggesting that the Prandtl-Kalman equation based on the mean flow log law can be used to reproduce the pipe friction coefficients.
