Experimental Velocity and Temperature Profiles for Air in Turbulent Pipe Flow

Abstract

It is often necessary to calculate the rate of heat transfer to fluids in situations for which no heat-transfer data exist. In many such cases, the rate of heat transfer can be calculated from known velocity distribution provided that the ratio of eddy diffusivity for heat to that for momentum is known. This paper describes an experiment in which the ratio was calculated from measured velocity and temperature profiles of air in fully developed flow in a pipe at uniform wall temperature. The ratio was found to vary with Reynolds number and position, and in all cases was above the value of unity used by many authors. The ratio approached a constant of about 1.4 very near the pipe wall.