The combined effects of angle of attack and louver angle of a winglet pair on heat transfer enhancement

A numerical analysis is conducted on the performance of a plate heat exchanger with a rectangular winglet pair to examine the combined effects of vortex generators and louver fins. Parameters considered are the Reynolds number, angle of attack, and louver angle. The Reynolds numbers are 300, 500, 700, 900, and 1100; angles of attacks are 15degrees, 30degrees, 45degrees, and 90degrees; and louver angles are 0degrees, 15degrees, 30degrees, and 45degrees. For evaluation of the heat exchanger performance, the ratio of heat transfer enhancement to flow loss penalty is introduced to take pressure loss into consideration. Results show that the best performance is achieved when the angle of attack is 30degrees and the louver angle is 15degrees. Variance is also analyzed, revealing that the most significant contribution is the angle of attack, and the next is the Reynolds number. The sole effect of the louver angle is found to be quite minor at a given angle of attack; however, its effect on heat exchanger performance appears substantial when it is combined with the variation of the angle of attack.