Comparative study of different vortex generator designs in corrugated channel for turbulent heat transfer enhancement

Abstract

• Vortex generators (VGs) in corrugated channels significantly enhance heat transfer by generating secondary flows, reducing wall recirculation, and thinning the thermal boundary layer. • Three VG designs concave-up (CUVG), concave-down (CDVG), and straight (SVG) were compared, showing distinct effects on flow structures and thermal performance. • CUVGs achieve the highest heat transfer enhancement (∼77 %), while SVGs provide the best balance between heat transfer increase and pressure drop (PEC ≈ 0.94). • Turbulent kinetic energy near the walls is intensified by VGs, promoting convective mixing and more uniform heat transfer along the channel. In this study, we numerically investigated the enhancement of heat transfer and pressure drop characteristics using vortex generators (VGs) inside a corrugated channel. This study focuses on novel VG shapes: concave-up vortex generators (CUVGs), concave-down vortex generators (CDVGs), and straight vortex generators (SVGs). These shapes were chosen for consistency with the corrugated wall to guide the fluid more smoothly along the wall. The model was solved using ANSYS Fluent, a commercial software based on the finite volume method and known for its conservation properties. For the turbulence model, we used the SST k–ω model because of its accuracy in capturing the flow near the walls. The vortex generators had a significant effect on the thermal and hydraulic performance. They enhance heat transfer by directing the fluid toward the wall, increasing the local velocity, and reducing the thickness of the thermal boundary layer. The CUVGs exhibited a higher heat transfer enhancement, reaching 77% at a Reynolds number of 30,000, followed by the CDVGs and SVGs, albeit with pressure drop penalties. To balance these effects, the PEC showed that SVGs had the best balance, reaching approximately 0.94, which is close to one.