Heat transfer enhancement using delta-wing streamwise vortex generators

Resumo

In this work, a three-dimensional thermo-fluid dynamics simulation using the multiphysics code Code Saturne
is carried out, in order to analyze the performance of delta-wing vortex generators for enhancing the heat exchange

in panel type radiators. These radiators are widely used in electric power transformers. The study is focused on nat-
ural convection and buoyancy-driven flows, which are common working conditions for this type of heat exchanger.

First, the performance of a single delta wing which is placed between parallel vertical plates is analyzed. The best
combination of characteristic parameters (aspect ratio, angle of attack) to obtain the highest thermal enhancement
factor is established. 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 dynamics 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%.