Numerical simulation of flow and heat transfer characteristics in wavy fin-and-tube heat exchanger with novel combined longitudinal vortex generators

The air-side fluid flow and heat transfer characteristics of wavy fin-and-tube heat exchanger with rectangular winglet pairs and combined rectangular winglet pairs were numerically analyzed. The numerical results show that the increase of the six parameters of combined rectangular winglet pairs can result in the increase of heat transfer and pressure drop. The longitudinal vortex generator has the best heat transfer performance, when the distance from the centerline and the borderline is 0.975mm and 1.8mm respectively in the downhill region and the optimum main attack angle of the combined winglet is 30°.