Heat transfer enhancement in panel type radiators using delta-wing vortex generators

Abstract

In this paper, a three-dimensional numerical simulation is used to analyze the performance of delta-wing vortex generators for enhancing the heat exchange in panel type radiators, which are widely used in electric power transformers. The study is focused on natural convection and buoyancy-driven flows, which are common working conditions for this type of heat exchanger. First, the performance of a single delta wing between parallel vertical plates is analyzed to establish the best combination of characteristic parameters to obtain the highest thermal enhancement factor. It is found that separating the vortex generator from the surface of the panel has positive effects in this sense. Then, with the selected configuration, a set of delta-wing arrays is placed on the surface of the heat exchanger, and the resulting thermo-fluid dynamic is analyzed. The total heat flux and local/global heat exchange coefficients are reported. Using these passive devices, the overall heat transfer improves by 12%.