Convection enhancement using composite vortex generator

Abstract

This paper presents an original concept of using composite flexible flapping vortex generator mounted on a heat sink fin for air side heat transfer augmentation. The main aim is to combine the advantages of hard and soft winglets in a composite one for having the highest possible enhancement. The proposed composite vortex generator, which is made with a thin elastic sheet is responsible for enhancing heat transfer and mixing quality performances in laminar convection air flow in a heat sink. The merged vortical structures due to oscillation by winglet swept out the thermal boundary layer and enhance thermal mixing between the fluid near the heated fin and the channel core flow. This novel concept is demonstrated using numerical simulation of the flow field with considering a two-way strongly coupled fluid-solid interaction approach in transient condition. The set of governing equations including, the continuity, momentum, and energy for a 2-D forced convection air flow are solved by the finite element method using the COMSOL Multi-Physics. The present findings show 148%, 116% and 121% increases in the cooling rate by the composite and the two hard and soft homogeneous winglets, respectively. Numerical results are validated against the numerical data reported in the literature.