Numerical study of fluid flow and convective heat transfer over multi-cylindrical obstacles in a channel using the lattice Boltzmann method

Abstract

The aim of this work is devoted to study the hydrodynamic and thermal behavior of fluid flowing around multi-cylindrical obstacles confined inside a 2D plane horizontal channel with constant-cool parallel plates. For this purpose, numerical simulations using the lattice Boltzmann method (LBM) based on double-distribution functions (DDFs) with a D2Q9 scheme is used to compute both velocity and temperature fields. The developed model is validated against established analytical and numerical results available in literature and the deviation does not exceed 2%. For a comprehensive parametric study, numerous calculations have been done for several parameters such as Reynolds number ( 10 ≤ Re ≤ 200 ), Prandtl number ( 0.1 ≤ Pr ≤ 2 ), blockage ratio ( 1 / 8 ≤ β ≤ 1 / 2 ) and number of obstacles. Effects on heat transfer evolution and flow characteristics are analyzed. Results are presented in terms of streamlines, isotherms and Nusselt numbers. The findings reveal a significant influence of the number of cylinders on both temperature and velocity distributions inside the channel. The average Nusselt number exhibits a linear correlation with Reynolds number, reaching a peak value at Re = 200 . These observations highlight the potential of LBM as an accurate and efficient tool to simultaneously predict the dynamic and thermal behavior of fluid flows in heat exchangers.