Experimental study on The Angle of attack effect on Hydraulic- Thermal performance of a cam-shaped tube with constant heat flux in cross flow

An experimental study was made to determine the effect of angle of attack on Hydraulic- Thermal Performance from a cam-shaped tube with constant heat flux in cross flow. Reynolds numbers based on an equivalent diameter are within 15500 < Re_(D_eq ) < 42000. Angle of attack is between 0 < α < 180 using air as fluid for cross flow. Results indicate that with increasing the angle of attack from 0˚ to 90˚ the mean nusselt number and drag coefficient increases about 7-13 and 114-122%, respectively. Drag coefficient and mean Nusselt number have been studied and the results demonstrate that in all Reynolds numbers the angles of 0˚ and 150˚ results in lowest and 90˚ results in the highest amount. A Hydraulic-Thermal comparison of the tube was made and the results show that the angles of 0˚ and 150˚ have the best performance comparing to other angles and the difference is about 31-125 %. Also angles of 0˚ and 150˚ are about 36-82 % better than a circular tube with equivalent diameter.