Simulation of natural convection in eccentric annuli between a square outer cylinder and a circular inner cylinder using local MQ-DQ method

A numerical study of the free convective flow in a horizontal eccentric annulus between a square outer cylinder and a heated circular inner cylinder is undertaken by using a local multiquadrics-hased differential quadrature (MQ-DQ) method. The method combines the advantages of the conventional differential quadrature (DQ) method for derivative approximation and the mesh-free nature of the multiquadrics (MQ) method. It is capable of simulating practical problems with much larger discretization systems compared to the traditional global MQ method. In this article, it is shown the local MQ-DQ method can accurately simulate the natural-convection problem at large Rayleigh number (1 0(6)). Numerical simulations are also carried out to study the effect of geometric parameters, such as eccentricities and angular positions, on the mean and local heat transfer rates.