METHOD FOR EVALUATING FLUID FRICTION AND METHOD FOR ESTIMATING FLUID FRICTION

摘要

PROBLEM TO BE SOLVED: To add a surface active agent to water flowing in a pipe, evaluate fluid friction generated by an influence of a pipe wall surface, and rationally perform this operation. SOLUTION: Relating to a vortex formed in a wall surface boundary layer of a current flowing in a pipe, based on hydro dynamic characteristic time of the vortex defined by a vortex diameter and a rotational speed of the vortex or a product dp0×D of a pressure loss dp0 generated by a flow and its represented length D, fluid friction is evaluated or estimated.