SR13  Mecânica dos Fluidos    Titulo: MULTIPOLE EXPANSION ALGORITHM APPLIED TO BIOT-SAVART CALCULATIONS OF PARTICLE INTERACTIONS   Resumo : ABSTRACT. IN A SYSTEM OF N PARTICLES A DIRECT CALCULATION OF THE INTERACTION BETWEEN PARTICLES USING THE BIOT-SAVART LAW REQUIRES N2 OPERATIONS PER TIME STEP, WHEREAS THE PARTICLE-BOX SCHEME OF THE MULTIPOLE EXPANSION ALGORITHM REQUIRES ONLY NLOGN OPERATIONS. THE LATTER AL-GORITHM MAY BE USED TO CALCULATE THE CONVECTIVE MOTION OF DISCRETE VORTICES THAT MODEL THE VORTICITY IN A 2-D SIMULATION OF THE INCOMPRESSIBLE, UNSTEADY FLOW AROUND A BODY. IN THIS PA-PER WE STUDY THE MAIN NUMERICAL PARAMETERS THAT INFLUENCE THE PERFORMANCE OF THE (FASTER) MULTIPOLE EXPANSION ALGORITHM OF THE PARTICLE-BOX TYPE: THE NUMBER OF VORTICES, THE NUMBER OF BOXES AND THE NUMBER OF VORTICES PER BOX. WE EVALUATE THE SPEED-UP GAINED WITH THE PARTI-CLE-BOX SCHEME, AS WELL AS WE ASSESS THE ERRORS INVOLVED IN THE COMPUTATION OF THE INDUCED VELOCITIES COMPARED TO THE DIRECT VORTEX-VORTEX CALCULATION. KEYWORDS: VORTEX METHOD, MULTIPOLE, BIOT-SAVART LAW, NUMERICAL METHODS     Autores : Bodstein, Gustavo C.R. Guedes, Vanessa Gonçalves Hirata, Miguel Hiroo     Trabalho Completo :   COBEM99 | Comissão  Organizadora | Palestras | Sessões Técnicas | Autor | Simpósios e Sessões Especiais | Revisores |  Título  dos  Trabalhos | Local