HEAT-TRANSFER AND PRESSURE-DROP CHARACTERISTICS OF AN ARRAY OF PLATES ALIGNED AT ANGLES TO THE FLOW IN A RECTANGULAR DUCT

The heat transfer and pressure drop characteristics of an array of plates, aligned at various angles of theta equals 20-35 degree to the direction of air flow in a rectangular, straight duct, have been investigated experimentally in the range of Reynolds numbers between 350 and 5000. The heat transfer coefficients of the forward and back sides of the plates have been separately determined, and the average coefficient between the two closely approximate the laminar short duct theory at low Reynolds numbers less than equivalent to 1200 and is nearly independent of the angle of alignment with respect to the air flow direction. However, at higher Reynolds number (N//R//e//,//D//h greater than equivalent to 1500) the average coefficient deviates significantly from the theory. The pressure drop measurements through the plate array showed that the streamwise, per-row coefficient K//p is a function of only the plate angle and independent of the Reynolds number.