A multi-domain approach for smoothed particle hydrodynamics simulations of highly complex flows

An efficient and accurate method is proposed to solve the incompressible flow momentum and continuity equations in computational domains partitioned into subdomains in the framework of the smoothed particle hydrodynamics method. The procedure does not require any overlap of the subdomains, which would result in the increase of the computational effort. Perfectly matching solutions are obtained at the surfaces separating neighboring blocks. The block interfaces can be both planar and curved surfaces allowing to easily decompose even geometrically complex domains. The smoothing length of the kernel function is maintained constant in each subdomain, while changing between blocks where a different resolution is required. Particles leaving each block through the interfaces are deactivated and correspondingly new particles are generated at the neighboring block using a dynamically adaptive procedure to control their frequency of release. No splitting and coalescing method is thus employed to take into account the different size and mass of the particles going through the interfaces. Mass conservation is guaranteed during the procedure, which is a challenging task in a Lagrangian method based on the domain decomposition. The test cases in both 2D and 3D approximation show the accuracy of the method and its ability to strongly reduce the computational efforts through a multi-resolution approach.