An accurate interpolating scheme for semi - Lagrangianadvection on an unstructured mesh for oceanmodelling
نویسندگان
چکیده
The semi-Lagrangian method is used for advection experiments on an irregular grid. A cosine hill is advected using a speci ed ow eld corresponding to solid body rotation. A major di culty is to nd an interpolator which is at least fourth order accurate on an unstructured mesh. Such accuracy is needed for the treatment of Rossby waves in ocean models. We develop such a method using a dual kriging interpolating scheme. The results are better than fourth order accurate, as shown by comparison with bicubic spline interpolation on a structured grid. Such accuracy is maintained for an unstructured triangular grid. The dissipation and dispersion of the cosine hill remain small, even after many rotation periods. The increase in computational cost is signi cant even if the interpolation is performed separately on smaller subdomains. However, by taking advantage of the increased exibilty of unstructured meshes and accuracy of the kriging approach, it is possible to achieve the same accuracy at a reasonable computational cost compared to traditional methods.
منابع مشابه
Adaptive Unstructured Grid Generation Scheme for Solution of the Heat Equation
An adaptive unstructured grid generation scheme is introduced to use finite volume (FV) and finite element (FE) formulation to solve the heat equation with singular boundary conditions. Regular grids could not acheive accurate solution to this problem. The grid generation scheme uses an optimal time complexity frontal method for the automatic generation and delaunay triangulation of the grid po...
متن کاملA Hermite-Type Adaptive Semi-Lagrangian Scheme
Adaptive semi-Lagrangian schemes for solving the Vlasov equation in the phase space have recently been developed. They include wavelet techniques (Gutnic et al., 2004; Gutnic et al., 2005), the moving mesh method (Sonnendrücker et al., 2004), and hierarchical finite element decomposition (Campos Pinto and Mehrenberger, 2004; Campos Pinto and Mehrenberger, 2005). One main advantage of the latter...
متن کاملAdaptive Solution of Steady Two Dimensional Flow on an Unstructured Grid
Two-dimensional Euler equations have been solved on an unstructured grid. An upwind finite volume scheme, based on Roes flux difference splitting method, is used to discretize the equations. Using advancing front method, an initial Delaunay triangulation has been made. The adaptation procedure involves mesh enrichment coarsening in regions of flow with high low gradients of flow properties, acc...
متن کاملAdaptive Solution of Steady Two Dimensional Flow on an Unstructured Grid
Two-dimensional Euler equations have been solved on an unstructured grid. An upwind finite volume scheme, based on Roe's flux difference splitting method, is used to discretize the equations. Using advancing front method, an initial Delaunay triangulation has been made. The adaptation procedure involves mesh enrichment coarsening in regions of flow with high low gradients of flow properties, ac...
متن کاملIncompressible laminar flow computations by an upwind least-squares meshless method
In this paper, the laminar incompressible flow equations are solved by an upwind least-squares meshless method. Due to the difficulties in generating quality meshes, particularly in complex geometries, a meshless method is increasingly used as a new numerical tool. The meshless methods only use clouds of nodes to influence the domain of every node. Thus, they do not require the nodes to be conn...
متن کامل