6533b839fe1ef96bd12a665a

RESEARCH PRODUCT

Free-surface flows solved by means of SPH schemes with numerical diffusive terms

Andrea ColagrossiMatteo AntuonoSalvatore MarroneDiego Molteni

subject

Convergence testsGeneral Physics and AstronomyFluid-structure impact problemsSPH pressure evaluationSmoothed particle hydrodynamicsSystem of linear equations01 natural sciences010305 fluids & plasmasSmoothed-particle hydrodynamicsViscositySmoothed particle hydrodynamicSpeed of sound0103 physical sciencesConvergence testsFree-surface flow0101 mathematicsFree-surface flowsPhysicsInternal energyMechanics010101 applied mathematicsFluid-structure impact problemHardware and ArchitectureFree surfaceWeak-compressibilitySmoothing

description

A novel system of equations has been defined which contains diffusive terms in both the continuity and energy equations and, at the leading order, coincides with a standard weakly-compressible SPH scheme with artificial viscosity. A proper state equation is used to associate the internal energy variation to the pressure field and to increase the speed of sound when strong deformations/compressions of the fluid occur. The increase of the sound speed is associated to the shortening of the time integration step and, therefore, allows a larger accuracy during both breaking and impact events. Moreover, the diffusive terms allows reducing the high frequency numerical acoustic noise and smoothing the pressure field. Finally, an enhanced formulation for the second-order derivatives has been defined which is consistent and convergent all over the fluid domain and, therefore, permits to correctly model the diffusive terms up to the free surface. The model has been tested using different free surface flows clearly showing to be robust, efficient and accurate. An analysis of the CPU time cost and comparisons with the standard SPH scheme is provided.

10.1016/j.cpc.2009.11.002http://www.cnr.it/prodotto/i/177979