SPH光滑粒子动力学ppt课件

Institute of Engineering Thermophysics工程热物理研究所Smoothed Particle HydrodynamicsInstitute of Engineering Thermophysics工程热物理研究所ContentsApplicationsThe advantages of SPHBasic ideas of SPHBackgroundInstitute of Engineering Thermophysics工程热物理研究所ContentsApplicationsThe advantages of SPHBasic ideas of SPHBackgroundInstitute of Engineering Thermophysics工程热物理研究所BackgroundNumerical simulation is a very important approach.Grid-based numerical methods suffer from difficulties in some aspects.The major difficulties are inherited from the use of grid or mesh.Institute of Engineering Thermophysics工程热物理研究所BackgroundMeshfree methodMeshfree particle methods(MPMs)Smoothed particle hydrodynamicDPD,MD,SPH etc.Meshfree method can deal with the above problemsSPHOne of the oldest meshfree particle methodsInstitute of Engineering Thermophysics工程热物理研究所ContentsApplicationsThe advantages of SPHBasic ideas of SPHBackgroundInstitute of Engineering Thermophysics工程热物理研究所Basic Ideas of SPH 1.In smooth particle method the fluid is represented as a set of particles that carry the properties of the fluid and interact according to equation of motion.The equation are derived in a clear and consistent way from the continuum equation and consitutive relation for the system.Institute of Engineering Thermophysics工程热物理研究所Basic Ideas of SPH2.SPH is a integral representation.Institute of Engineering Thermophysics工程热物理研究所Basic Ideas of SPH3.The kernel approximation is then further approximated using particle.Particle approximationThe particle approximation is performed at every time step The use of the particle depends on the distribution of the particlesInstitute of Engineering Thermophysics工程热物理研究所Basic Ideas of SPH4.The particle approximations are performed to all terms related to field functions.Ordinary differtial equationsParticle differential equationsThe ODEs are solved at every time step,and to abtain the time history of all variables for all particles.5.becomegetInstitute of Engineering Thermophysics工程热物理研究所Basic Ideas of SPHlThe fluid is presented by particle which follow the fluid motion.n Each particle carries mass,velocity and other qualiticle.u SPH formulation is directly based on the resolution of macroscopic governing equation of fluid flow.6.SummaryInstitute of Engineering Thermophysics工程热物理研究所ContentsApplicationsThe advantages of SPHBasic ideas of SPHBackgroundInstitute of Engineering Thermophysics工程热物理研究所The Advantages of SPHSPH is a Lagrangian meshfree particle method.The accuracy,stability and adaptively are acceptable.Application are very wide.SPH is suitable to follow large surface deformation involving free surface and interfacial.Discrete system Continuum systemsMicro-scaleMacro-scaleInstitute of Engineering Thermophysics工程热物理研究所ContentsApplicationsThe advantages of SPHBasic ideas of SPHBackgroundInstitute of Engineering Thermophysics工程热物理研究所ApplicationsCase one-droplet impacting liquid surface1.surface tension-its macroscopic description Young-Laplace equation 2.Three types particles-real particles side-wall virtual particles image virtual particle3.Two types of boundaries-surface boundary rigid boundaryConclusion:SPH method has a certain superiority in simulating the strong non-linear transient free surface flow.Numerical simulation of droplet impacting liquid surface by SPH.(2011)LI DaMing.School of Civil Engineering,Tianjin UniversityInstitute of Engineering Thermophysics工程热物理研究所ApplicationsCase two-coalescence of colliding drops1.The background of binary coalescence.2.The dimensionsionless numbers.3.The types of outcome.4.The process of colliding.Coalescence of colliding van der Waals liquid drops.(2005)attractive forcecohesive pressureV D W equationsurface tensionI abtain informationsUniversite de Montpellier IIInstitute of Engineering Thermophysics工程热物理研究所Applications Modeling of surface tension and contact angles with smoothed particle hydrodynamics(2005)Case three-Flow through fracture junctionssurface tensioncontact anglespairwise fluid-fluid and fluid-solid particle-particle interactionsNumerical experimentThe results were in qualitative agreement.Institute of Engineering Thermophysics工程热物理研究所