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Flow Analysis of Heat Exchanger with Delta Winglet Vortex Generators on CFD

Fin-tube heat exchangers are widely used in refrigeration systems. To improve the performance of fin-tube heat exchangers, the shape of plain fin was developed in slit fin and louver fin. These pins have higher heat transfer performance as well as larger pressure drop. Recent studies of a delta winglet vortex generators(DWVG) show less heat transfer capacity than louver fin. However, the DWVG have very small pressure drop. This paper compares the performance for the plain fin and DWVG fin in terms of flow characteristics and heat transfer based on CFD analyses. The DWVG generate vortex and delayed flow separation and leads to a reduction of a wake region behind a tube. The results show that the DWVG produce improved heat transfer and reduced pressure drop compared to a plain fin. This result is opposite to the Reynolds analogy.