روش شبکه بولتزمن حرارتی مرتبه دوم در انتقال حرارت جابه¬جایی آزاد در محفظه¬های غیرمربعی

in this paper, two dimensional natural convection heat transfer in non-square cavities such as triangle, trapezoid, quadrant-circle and semi-circular are investigated via lattice boltzmann method. the prandtl number is taken as 0.71 that corresponds to that of air. the results show that, when the flow pattern consists of two rotating cell, there is a extremum point in the variations of the local nusselt number. in the case of single cell pattern, according to the boundary conditions, the variations of the local nusselt number are changed. the obtained results of the lattice boltzmann method are validated with those presented in the literature and show that the lattice boltzmann method can simulate the heat transfer and flow pattern in the complex cavities. analysis of heat transfer in such geometries especially by using the second order boundary conditions on the curved surfaces is the main novelty of the present work and it has many applications in the electronic cooling.