Spreading Resistance of Isoflux Rectangles and Strips on Compound Flux Channels

Abstract

The general expression for the spreading resistance of an isoe ux, rectangular heat source on a two-layer rectangular e ux channel with convective or conductive cooling at one boundary is presented. The general expression depends on several dimensionless geometric and thermal parameters. Expressions are given for some two- and three-dimensional spreading resistances for two-layer and isotropic e nite and semi-ine nite systems. The effect of heat e ux distribution over strip sources on two-dimensional spreading resistances is discussed. Tabulated values are presented for three e ux distributions, the true isothermal strip, and a related nonisoe ux, nonisothermal problem. For narrow strips, the effect of the e ux distribution becomes relatively small. The dimensionless spreading resistance for an isoe ux square source on an isotropic square e ux tube is discussed, and a correlation equation is reported. The closed-form expression for the dimensionless spreading resistance for an isoe ux rectangular source on an isotropic half-space is given.