Natural Convection and Entropy Generation in Γ-Shaped Enclosure Using Lattice Boltzmann Method

This work presents a numerical analysis of entropy generation in Γ-Shaped enclosure that was submitted to the natural convection process using a simple thermal lattice Boltzmann method (TLBM) with the Boussinesq approximation.  A ۲D thermal lattice Boltzmann method with ۹ velocities, D۲Q۹, is used to solve the thermal flow problem. The simulations are performed at a constant Prandtl number (Pr = ۰.۷۱) and Rayleigh numbers ranging from ۱۰۳ to ۱۰۶ at the macroscopic scale (Kn = ۱۰-۴). In every case, an appropriate value of the characteristic velocity is chosen using a simple model based on the kinetic theory.  By considering the obtained dimensionless velocity and temperature values, the distributions of entropy generation due to heat transfer and fluid friction are determined. It is found that for an enclosure with high value of Rayleigh number (i.e., Ra=۱۰۵), the total entropy generation due to fluid friction and total Nu number increases with decreasing the aspect ratio.

کلیدواژه ها:

Entropy generation ، Lattice Boltzmann Method ، natural convection ، Γ-Shaped enclosure