INVESTIGADORES
NIGRO Norberto Marcelo
artículos
Título:
Numerical Simulation of Transient Free Surface Flows Using a Moving Mesh Technique
Autor/es:
BATTAGLIA LAURA; D'ELIA JORGE; STORTI MARIO; NIGRO NORBERTO
Revista:
JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME
Editorial:
ASME JOURNALS
Referencias:
Año: 2006 vol. 72 p. 1017 - 1025
ISSN:
0021-8936
Resumen:
In this work, transient free surface flows of a viscous incompressible fluid are numerically solved through parallel computation. Transient free surface flows are boundary-value problems of the moving type that involve geometrical nonlinearities. In contrast to more conventional computational fluid dynamics (CFD) problems, the computational flow domain is partially bounded by a free surface which is not known a priori, since its shape must be computed as part of the solution. In steady-flow the free surface is obtained by an iterative process, but when the free surface evolves with time the problem is more difficult as it generates large distortions in the computational flow domain. The incompressible Navier- Stokes numerical solver is based on the finite element method with equal order elements for pressure and velocity (linear elements), and it uses a Streamline Upwind/Petrov-Galerkin (SUPG) scheme (Hughes, T. J. R. and Brooks, A. N., 1979, “A Multidimensional Upwind Scheme With no Crosswind Di_usion”, In Finite Element Methods for Convection Dominated Flows, ASME ed., 34.AMD, New York, pp. 19-35, and Brooks, A. N., and Hughes, T. J. R., 1982, “Streamline Upwind/Petrov-Galerkin for Convection Dominated Flows With Particular Emphasis on the Incompressible Navier-Stokes Equations”, Comput. Methods Appl. Mech. Eng.,32, pp. 199-259) combined with a Pressure-Stabilizing/Petrov-Galerkin (PSPG) one (Tezduyar, T. E., 1992, “Stabilized Finite Element Formulations for Incompressible Flow Computations”, Adv. Appl. Mech., 28, pp. 1-44, and Tezduyar, T. E., Mittal, S., Ray, S. E., and Shih, R., 1992, “Incompressible Flow Computations With Stabilized Bilinear and Linear Equal Order Interpolation Velocity-Pressure Elements”, Comp. Methods Appl. Mech. Eng., 95, pp. 221-242). At each time step, the fluid equations are solved with constant pressure and null viscous traction conditions at the free surface and the velocities obtained in this way are used for updating the positions of the surface nodes. Then, a pseudo elastic problem is solved in the fluid domain in order to relocate the interior nodes so as to keep mesh distortion controlled. This has been implemented in the PETSc-FEM code (PETSc-FEM: a General Purpose, Parallel, Multi-Pysics FEM Program GNU General Public License (GPL), http://www.cimec.org.ar/petscfem) by running two parallel instances of the code and exchanging information between them. Some numerical examples are presented.