Free-stream Turbulence Effects on Heat and Mass Transfer from Spheres : 1st Report, Average Transfer Coefficients

Abstract

The effects of free-stream turbulence on the average heat and mass transfer coefficients around spheres were experimentally investigated. The Reynolds numbers ranged from 3.5×10³ to 1.4×10⁵ and the turbulence intensity was up to 8.5%. The average mass transfer rates measured by means of naphthalene sublimation technique were found to increase in direct proportion to the turbulence intensity, though the rate of increase decreased in the flow above the critical Reynolds number. The results of heat transfer were compared with those of mass transfer experments in order to study the effects of free-stream turbulence on the analogy between heat and mass transfer.