In this paper, natural convection flows in concentric and eccentric annuli are studied using a new numerical method, namely local moving least square-one dimensional integrated radial basis function networks (LMLS-1D-IRBFN). The partition of unity method is used to incorporate the moving least square (MLS) and one dimensional-integrated radial basis function (1D-IRBFN) techniques in an approach that leads to sparse system matrices and offers a high level of accuracy as in the case of 1D-IRBFN method. The present method possesses a Kronecker-Delta function property which helps impose the essential boundary condition in an exact manner. The method is first verified by the solution of the two-dimensional Poisson equation in a square domain with a circular hole, then applied to natural convection flow problems. Numerical results obtained are in good agreement with the exact solution and other published results in the literature
