Enhancement of Heat Transfer in a Short Rectangular Channel with Substantial Deflection of Inlet Velocity from Axial Direction

Abstract

Experimental and theoretical investigation of heat transfer and hydrodynamics of a heated short rectangular channel which is an element of a header system with a plane rectangular header of constant cross section is carried out. Depending on the position of the inlet into the channel relative to the inlet section of the supply header, the flow rate and flow inlet angle as well as the total velocity of the flow change in the header, which is associated with the presence of a transit flow through the supply header. The indicated factors exert a substantial influence on the heat transfer coefficients in the channel. For a more correct comparison of experimental data with the case of an axial inlet, heat transfer in the test channel was also determined in the absence of the transit flow, i.e., practically for the case of an axial inlet. On maximum deviation of the flow inlet angle from the axial one, an increase in the rate of heat transfer in comparison with the axial inlet was from 60% to 100%.