An Efficient Generalized Finite Difference Method for Elliptic PDEs
摘要
In recent years, considerable research has been devoted to meshless methods for solving differential equations for several reasons. Unlike traditional mesh-based approach, meshless methods are able to capture complex geometries more accurately and eliminate the need for mesh generation prior to simulation. This is particularly beneficial in boundary layer flow problems, where achieving precision near boundaries is challenging due to rapid variations in flow behavior. Generalized Finite Difference (GFD) method is one such meshless method that uses the idea of Taylor’s series expansion. Literature survey reveals that GFD method is able to solve both linear and nonlinear Partial Differential Equations (PDEs) efficiently. However, it is a computationally expensive method. This is because the process of computation requires the Taylor series expansion along the neighboring nodes. This results in a system of equations for each node, and hence the matrix inversion since the right-hand side is also unknown. More nodes have to be used to increase the accuracy. These all result in the high computational cost. A comparison of numerical efficiency requires measuring the computational CPU time needed by the schemes to achieve the same level of accuracy. To overcome the computational cost of GFD while maintaining the advantages provided by the meshless methods over mesh-based methods, we developed two Multilevel GFD methods, namely V-cycle Multilevel GFD and Bootstrap Multilevel GFD methods. Both linear and nonlinear elliptic PDEs have been solved with the help of the above-developed algorithms with uniform and non-uniform distribution of nodes in the domain. It is observed that the method helps in decreasing the CPU time significantly when compared with single-level GFD method. The multilevel algorithms also improve the order of convergence in some cases.