Numerical investigation of conjugate heat transfer and flow performance of a fin and tube heat exchanger with vortex generators

Vortex generator is considered as an effective device for augmentation of the thermal-hydraulic performance of a heat exchanger. The aim of present study is to examine the influence of vortex generators on a double fin and tube heat exchanger performance. Vortex generator of rectangular winglet type is chosen and investigated at different angles of attack 0 , ??10 and ??20 with the flow direction. Three-dimensional numerical model is developed and simulations are performed for a Reynolds number range 5000 Re 11000 taking conjugate heat transfer into account. The heat transfer and pressure loss characteristics are determined and analyzed for an in-line configuration of a fin and tube heat exchanger. In order to evaluate the enhancement in the performance on an equitable basis, the heat exchanger with plain fin surface is considered as a reference design. Results show that the angle of attack of a vortex generator has a significant impact on the volume goodness factor, and enhance the thermal performance of a fin and tube heat exchanger in comparison to the design with plain fin. The vortex generator at an angle of attack ??10 is found to perform superior over the Reynolds number range studied. At Re = 5000, the vortex generator with an angle of attack ??10 increases the volume goodness factor by 32% with respect to the baseline heat exchanger design.