Heat transfer at an upstream-facing 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/S0017-9310(81)80008-7
- 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