Large Eddy Simulation of the flow and heat transfer in a half-corrugated channel with various wave amplitudes

Large Eddy Simulation (LES) of turbulent flow and convective heat transfer over a half-corrugated channel is presented in this paper. Simulations are performed for various ranges of the normalized wave amplitudes, AM=0-0.15 (the ratio of wave height to wave length). The Reynolds number based on the bulk velocity is chosen as Reb=10000 and the Prandtl number is Pr = 0.71. A comparison between the DNS and LES results of a plane channel (AM=0) at Reτ=395 is also performed. The obtained results indicate that the region of recirculating flow depends strongly on the wave amplitude. This study shows that the Nusselt number (Nu) increases by increasing the wave amplitude until a specific value then it remains approximately constant. The thermal performance parameter (JF) is used as a measure for the heat transfer enhancement relative to the pressure drop and it is found that the maximum values of Nu and JF appear at AM=0.1, which hence correspond to the optimum value of the wave amplitude.