Vortex Preservation Using Coupled Eulerian–Lagrangian Solver

This Paper presents a coupled vortex particle method–computational fluid dynamics solver. The vortex particle method is used to prevent dissipation of the vortex structure on coarse computational fluid dynamics meshes. Implementation of the approach uses the split velocity method that specifies the fluid velocity as the sum of the induced vortex particle velocity and a remaining velocity. Dissipation of the vortex velocities on coarse meshes is removed, and the computational fluid dynamics equations solved for the remaining velocity have a form identical to those for a moving mesh, but with additional source terms. The coupled solver is demonstrated on a selection of two-dimensional test cases, and the results are compared to the solutions of the computational fluid dynamics solver on its own using a coarse mesh and a fine mesh. It is shown that the coupled solver preserves the vortices on a coarse mesh and is computationally more efficient than using the fine mesh.