Heat Transfer and Flow Structure in Turbulent Flows in a Rectangular Channel with Built-in Vortex Generators

Counter rotating longitudinal vortices produced by a winglet pair in a channel is known to enhance heat transfer. In the present work the flow structure and heat-transfer enhancement by a triangular winglet pair has been studied. A triangular winglet pair type vortex generator is placed in turbulent channel flow. Each winglet pair induces longitudinal vortices behind it. Computations are done by solving the steady state, three-dimensional, incompressible Navier–Stokes and energy equation using finite volume method. Results that obtain using shear-stress transport (SST) model, are close to experimental results of Tiggelbeck et al. It is observed that as compared to a channel without winglets, local heat transfer is enhanced several times but the average heat transfer is enhanced by 85% when a winglet pair is employed. Effects of angle of attack on the heat transfer augmentation and pressure drop and compactness are presented.

کلیدواژه ها:

heat transfer enhancement ، vortex generator ، angle of attack ، longitudinal vortices