Pressure Loss and Heat Transfer Characterization of a Cam-Shaped Cylinder at Different Orientations

Abstract

Pressure drag coefficient and heat transfer are experimentally investigated around a single noncircular cylinder in cross-flow under angle of attack 0 deg<α<360 deg and Reynolds number 1.5×104<Reeq<4.8×104 based on equivalent diameter of a circular cylinder. The results show that the trend of pressure drag coefficient against the angle of attack has a wavy shape but the wavy trend of the Nusselt number is smoother relative to the drag coefficient behavior. It is found that for l∕Deq=0.4 and over the whole range of the Reynolds number, the pressure drag coefficient has a minimum value of about CD=0.4 at α=30 deg, 180 deg, and 330 deg and a maximum value of about CD=0.9 at α=90 deg and 270 deg. The corresponding value of the mean Nusselt number to that of the equivalent circular tube is 1.05<Nu¯cam∕Nu¯cir<1.08 at α=90 deg and 270 deg as well as 0.87<Nu¯cam∕Nu¯cir<0.92 at α=30 deg and 180 deg.