A Correlation for Heat Transfer and Wake Effect in the Entrance Region of an In-Line Array of Rectangular Blocks Simulating Electronic Components

Abstract

An experimental investigation is carried out to study heat transfer in the entrance region of an array of rectangular heated blocks. The focus of the work is on the entrance heat transfer coefficients and the associated thermal wake effects. The experiments were performed with air as the working fluid. The geometric parameters of the array were varied in the range identified with B/L = 0.5, S/L = 0.128–0.33, and H/L = 0.128–1. The Reynolds number, based on the height above the blocks and the fluid mean velocity in the bypass channel, ranged from 3000 to 15,000. The adiabatic heat transfer coefficients and thermal wake effects are correlated for the entrance region. These correlations are incorporated into a user-friendly FORTRAN program, which can be used by the engineers to predict the working temperatures of the components of circuit boards with similar layout. A typical computer output indicated that the mean deviation between the measured and predicted temperatures is 11.0 percent.