Heat transfer at an upstreamfacing surface washed by fluid en route to an aperture in the surface
Abstract
Forced convection heat transfer coefficients were measured at a plane surface pierced by an aperture (or tube inlet) of diameter (d) into which fluid flows from a large upstream space. Heat transfer effects were confined to a portion of the surface contained within an annulus of outer diameter D which surrounds the aperture. The experiments were carried out for several values of the d/D ratio ranging from 1/6 to 1/14.4, and for each fixed d/D the Reynolds number was varied parameterically over a range that spanned a factor of five. Dimensional analysis led to a Reynolds number involving the rate of mass flow through the aperture and the outer diameter of the thermall active region. The end result of the dimensional analysis indicated that for a fixed Prandtl number, the Nusselt number could depend on both Re and d/D. When the Nusselt number data for all cases were brought together on a single graph which spanned more than a decade in Reynolds number, no dependence on d/D was observed. It was also found that the average rate of heat transfer per unit area drops off sharply as the outer diameter of the thermally active annular region increases.
 Publication:

International Journal of Heat and Mass Transfer
 Pub Date:
 May 1981
 DOI:
 10.1016/S00179310(81)800087
 Bibcode:
 1981IJHMT..24..851S
 Keywords:

 Apertures;
 Convective Heat Transfer;
 Flat Surfaces;
 Fluid Flow;
 Forced Convection;
 Heat Transfer Coefficients;
 Upstream;
 Dimensional Analysis;
 Flow Velocity;
 Nusselt Number;
 Reynolds Number;
 Temperature Gradients;
 Fluid Mechanics and Heat Transfer