Nano scale lattice Boltzmann method to simulate the mixed convection heat transfer of air in a lid-driven cavity with an endothermic obstacle inside

摘要

Mix convection resulting from simultaneous natural and forced heat transfer in the air inside an inclined square lid-driven cavity containing an endothermic obstacle was investigated and numerically simulated. In this method, macroscopic parameters such as velocity and temperature are calculated by averaging microscopic parameters. Moreover, the impact of inclination on parameters such as velocity, temperature, Nusselt number and heat transfer were addressed in this study. The simulations were carried out using lattice Boltzmann method by assuming five different Richardson numbers and three different cavity inclination angles. Overall, the flow and heat transfer characteristics were analyzed in certain Richardson number and Grashof number ranges. It was concluded that for horizontal cavity, Nu(m) was maximized at Ri = 50 compared to other Richardson numbers at the same angle. Therefore, it is safe to say that forced convection leads to maximum heat transfer rate from the cavity at various inclinations while increasing gamma promotes free convection to the point where at gamma = 30 free convection becomes the dominant heat transfer mechanism and the maximum Num is obtained at Ri = 50 and gamma = 60. The Simulation approach of endothermic obstacle inside the cavity by applying nano scale method of lattice Boltzmann is presented at this work. (C) 2018 Elsevier B.V. All rights reserved.