NUMERICAL-SIMULATION OF PERIODIC BOUNDARY-CONDITION ON VORTEX FLOW

The unsteady inviscid flow of an incompressible fluid with a periodicity in one space direction is considered. This problem is numerically solved by means of a particle method and an asymptotic formulation for the velocity and stretching terms of the vorticity transport equation. This formulation combines the advantages of a fast computation and the elimination of the necessary truncation of the infinite series to be considered in the periodic Biot-Savart law. The method is applied to compute the evolution of contra-rotative vortex-filaments and is in good agreement with theoretical results obtained through linear analysis.