Effect of deflection angles on performances of finned oval tube heat exchanger applied to wind tunnel

Based on the structure of a wind tunnel heat exchanger, establishes a three-dimensional model of finned oval tube heat exchanger. Investigates the effects of deflection angles of finned oval tubes on heat transfer, pressure drop characteristics and uniformity of outlet air temperature field respectively. Because the equivalent diameter of the heat exchanger is small, the range of Re value is 3 500 to 5 200. The numerical simulation results show that the change of deflection angle of the tube affects the flow direction of the wake vortex, thereby changes the performance of the heat exchanger. With the increase of deflection angle of oval tube, the increasing trend of heat transfer performance slows down, while the pressure loss increases gradually. When the oval tube is deflected by 10 degrees, the heat exchanger not only has better overall performance, but also has better outlet air temperature uniformity.