Heat transfer performance analysis through inline and staggered grooved microchannel using lattice Boltzmann method

Abstract

The D2Q9 Bhatnagar-Gross-Krook (BGK) model, utilizing the Thermal Lattice Boltzmann Method (TLBM) to examine the temperature and mass transfer numerically across inline and staggered grooved microchannels. The conditions are (a) cold fluid at inlet and outlet, (b) walls are heated (c) relative roughness height is rh=4%, 8% and 12% according to channel height and (d) parabolic velocity profile at inlet and outlet section with slip flow at the walls for different Knudsen numbers from Kn=0.02 to 0.10. The study goals to examine the impact of temperature profiles, Nusselt number, average friction coefficients and performance analysis of smooth, inline and staggered grooved microchannels. The friction coefficient is defined as the ratio of the Poiseuille number (Pn) and Reynolds number (Re) and the dimensionless heat transfer recognized by the Nusselt number (Nu) has been studied to investigate the roughness effects of the surface. The result presented that the average friction increased gradually with the height of relative roughness and reduced significantly with growing Kn for both inclined and staggered grooved microchannels. In addition, compared to smooth, inline and staggered microchannels, the lowest friction occurred for smooth and the highest friction showed for inline grooved channels. The maximum average friction factor is depicted as 107.053 for inline grooved microchannels when rh=12% and Kn is 0.02. The extreme heat transfer rate is found to be 9.015 when the microchannel is smooth and Kn=0.02. The highest performance PE=1.013248 is exhibited by the staggered microchannel when Kn=0.02 and with rh=12%. Compared to the inline grooved channel, the staggered grooved microchannel has demonstrated better performance.