Effect of a flat plate on heat transfer and flow past a three side-by-side square cylinders using double MRT-lattice Boltzmann method

Abstract

In this work, a numerical study was carried out to simulate laminar flow and heat transfer characteristics in a 2D dimensional horizontal channel, including three heated square cylinders placed side-by-side and equally spaced. A controlled flat plate is inserted behind obstacles. The Double Multiple Relaxation Time Lattice Boltzmann Method (MRT-LBM) is adopted as the numerical method were using the MRT-D2Q9 model and the MRT-D2Q5 model to treat the flow and the temperature fields respectively. The problem regarded, in this paper, is a laminar and incompressible flow. The air (Pr = 0.71) is the fluid circulating in the channel, its physical properties, except the density, are supposed to be constant. The top and bottom channel walls are assumed to be adiabatic, the airflow incoming with cold temperature which is fixed to θc = – 0.5, each cylinder at a constant hot temperature equal to θh= 0,5. The flow is fully developed with a parabolic velocity profile at the inlet and at the outlet of the channel. also, in the outlet, the temperature and velocity gradients are assumed to be zero. The effects of plate position and length on the fluid flow and the heat transfer are examined in terms of streamlines and isotherms contours visualizations.