مشخصات پژوهش

In this paper the laminar incompressible flow equations are solved by an upwind least-squares meshless method. Difficulties in generating quality meshes, particularly in complex geometry cases a meshless method is increasingly used as a new numerical tool. The meshless methods only use clouds of nodes in the influence domain of every node. Thus, they don’t require the nodes to be connected to form a mesh and decrease the difficulty of meshing particularly around complex geometries. In the literature has been shown that generation of points in domain by the advancing front technique is an order of magnitude faster as compared to an unstructured mesh for a 3D configuration. The Navier–Stokes solver is based on the artificial compressibility approach and the numerical methodology is based on the higher-order Characteristic-Based (CB) discretization. The main objective of this research is using the CB scheme in order to prevent the instabilities. With this inherent upwind technique for estimating convection variables at midpoint no artificial viscosity is required at high Reynolds number. The Taylor least-squares method was used for calculation of spatial derivatives with normalized Gaussian weight functions. An explicit four stages Runge-Kutta scheme with modified coefficients was used for the discretized equations. To accelerate convergence, local time stepping is used in any explicit iteration for steady state test cases. The residual smoothing techniques are used to convergence acceleration, too. The capabilities of the developed 2D incompressible Navier-Stokes code with proposed meshless method are demonstrated by flow computations in a lid-driven cavity at four Reynolds numbers. Obtained results using new proposed scheme are presented which indicate good agreement with standard benchmark solutions in the literature. It was found that, Using the 3rd order accuracy for proposed method is efficient than its 2nd order accuracy discretization in terms of computational