Investigation of convective heat transfer and flow hydrodynamics in rectangular grooved channels


Zontul H., Hamzah H., Kurtulmuş N., Şahin B.

International Communications In Heat And Mass Transfer, cilt.126, ss.105366-105372, 2021 (SCI-Expanded)

Özet

An experimental and numerical investigation is conducted for convective heat transfer and flow characteristics in a channel with rectangular grooved top and bottom walls. The study is performed between 2 × 103and 6.5 × 103 of Reynolds numbers. Heat transfer experiments are conducted by applying constant heat flux to the channel upper and lower walls. The averaged Nusselt number, Nu, is presented as an indicator of heat transfer. In the experiments, 1.9–2.4 times larger Nu values were obtained by using grooved channels instead of straight channels. Pressure measurements show that the corrugated channel causes an increase in pressure loss. The Particle Image Velocimetry, PIV method is employed to reveal the flow hydrodynamics and its relation with convective heat transfer. Using the ability of the PIV method to provide instantaneous flow data, interactions between the recirculation flow bubbles in the grooves and the mainstream are observed. In the numerical part of the study, the k-ε turbulence model is used, and predicted results are found to be consistent with experiments. The validated numerical method is used to investigate the effect of groove aspect ratio on heat transfer and pressure drop.