Numerical Study of Natural Convection in an Inclined Triangular Cavity for Different Thermal Boundary Conditions: Application of the Lattice Boltzmann Method

摘要

A double-population Lattice Boltzmann Method (LBM) is applied to solve the steady-state laminar natural convective heat-transfer problem in a triangular cavity filled with air (Pr = 0.71). Two different boundary conditions are implemented for the vertical and inclined boundaries: Case I) adiabatic vertical wall and inclined isothermal wall, Case II) isothermal vertical wall and adiabatic inclined wall. The bottom wall is assumed to be at a constant temperature (isothermal) for both cases. The buoyancy effect is modeled in the framework of the well-known Boussinesq approximation. The velocity and temperature fields are determined by a D2Q9 LBM and a D2Q4 LBM, respectively. Comparison with previously published work shows excellent agreement. Numerical results are obtained for a wide range of parameters: the Rayleigh number spanning the range (10~3 - 10~6) and the inclination angle varying in the intervals (0° to 120°) and (0° to 360°) for cases I and II, respectively. Flow and thermal fields are given in terms of streamlines and isotherms distributions. It is observed that inclination angle can be used as a relevant parameter to control heat transfer in right-angled triangular enclosures.