The local RBF collocation method for solving the double-diffusive natural convection in fluid-saturated porous media

Abstract The local RBF (radial basis function) collocation method (LRBFCM) combined with the exponentially convergent scalar homotopy algorithm (ECSHA) is proposed to analyze the double-diffusive natural convection in parallelogrammic enclosures filled with fluid-saturated porous media. The LRBFCM, free from mesh and numerical quadrature, is proposed to efficiently and accurately analyze the double-diffusive natural convection. In comparing with other meshless methods, the concept of localization in LRBFCM can avoid the ill-conditioned and full matrix. By enforcing the satisfactions of governing equation at every interior node and boundary condition at every boundary node, a system of nonlinear algebraic equations (NAEs) will be formed by LRBFCM. Thus, the ECSHA is adopted to efficiently resolve the system of NAEs. The efficiency of the evolutionary process in solving NAEs is greatly improved since the calculation of the inverse of Jacobian matrix can be avoided. Two numerical examples will be provided to demonstrate the ability and accuracy of the proposed meshless scheme.