Friction and Heat-Transfer Measurements to Turbulent Pipe Flow of Water (Pr=7 and 8) at Uniform Wall Heat Flux

Abstract

Measurements are reported of overall test section friction and of local heat transfer for the case in which hydrodynamically developed turbulent flow of water enters a uniformly heated circular tube. Systematic data are given for various heating rates and are shown to extrapolate to the zero heating rate or constant fluid property condition. In the thermal entrance region, variable property results are shown to agree with the measurements of Hartnett and constant property results are shown to agree with the analytical results of Sparrow, Hallman, and Siegel. Variable property test section friction results are shown to follow the wall temperature rule of Eagle and Ferguson. Constant property heat-transfer results at Pr = 8 are shown to yield a Reynolds number exponent which increases systematically from 0.84 at Re = 15,000 to 0.87 at Re = 100,000. Nusselt numbers at Pr = 8 are in excellent agreement with the analytical results of Sparrow, Hallman, and Siegel.