Heat transfer enhancement by winglet-type vortex generator arrays in compact plain-fin-and-tube heat exchangers
- A. Joardar, A. M. Jacobi
- Int. J
Among tubular heat exchanger, fin tube types are the most widely used in refrigeration and air conditioning equipment. Efforts to enhance the performance of these heat exchangers included variations in the fin shape from a plain fin to a slit and louver type. In the context of heat transfer augmentation, the performance of vortex generator has also been investigated. Rectangular winglet vortex generators have recently attracted research interest, partly due to experimental data showing that their addition increases the performance of fintube heat exchanger. The efficiency of the rectangular winglet vortex generators widely varies depending on their size and shape, as well as locations where they are implemented. The present work represents a twodimensional numerical investigation of 4-row tube bank in staggered arrangement with rectangular vortex generators placed in common flow up configuration. The effects of the angle of attack (30 0 and 45 0 ) , width (5mm, 5.5mm, 6mm ) of vortex generators at position (∆x/∆y =1.3) are examined. It has been observed that overall Nusselt number of four row tubes increases by 18.68 46.38% and 38 55.86% with angles of 30 0 and 45 0 respectively with increase in pressure drop 9.26-56.35% and 38-190.3% with two angles used respectively , in comparison with case without vortex generators.