On the conditions at the boundary of a fluid in turbulent motion

Abstract

The object of the experiments was to determine the nature of the flow in the neighbourhood of the boundary of a fluid flowing in turbulent motion through a channel with parallel walls. The observations were made on air flowing through long pipes of circular cross section at mean rates of flow covering as wide a range as possible below and above the critical speed. The pipes used were 0. 269, 0. 714 and 12.7 cms. in diameter, and the range in experimental conditions varied from... The conclusions are that for speeds above the critical value as high as could be obtained, there is a layer of fluid of finite thickness at the boundary which is in laminar motion, and that the boundary condition is ... where the origin is taken in the boundary, and x is measured along the normal ; v is the velocity parallel to the boundary, mu is the coefficient of viscosity, R is the intensity of surface friction.