Incompressible SPH (ISPH) with fast Poisson solver on a GPU

    Research output: Contribution to journalArticlepeer-review

    Abstract

    This paper presents a fast incompressible SPH (ISPH) solver implemented to run entirely on a graphics processing unit (GPU) capable of simulating several millions of particles in three dimensions on a single GPU. The ISPH algorithm is implemented by converting the highly optimised open-source weakly-compressible SPH (WCSPH) code DualSPHysics to run ISPH on the GPU, combining it with the open-source linear algebra library ViennaCL for fast solutions of the pressure Poisson equation (PPE). Several challenges are addressed with this research: constructing PPE matrix every timestep on the GPU for the moving particles, optimising the limited GPU memory, and exploiting fast matrix solvers. The ISPH pressure projection algorithm is implemented as 4 separate stages, each with a particle sweep, including an algorithm for the population of the PPE matrix suitable for the GPU, and mixed precision storage methods. An accurate and robust ISPH boundary condition ideal for parallel processing is also established by adapting an existing WCSPH boundary condition for ISPH. A variety of validation cases are presented: an impulsively started plate, incompressible flow around a moving square in a box, and dam breaks (2-D and 3-D) which demonstrate the accuracy, flexibility, and speed of the methodology. Fragmentation of the free surface is shown to influence the performance of matrix preconditioners and therefore the PPE matrix solution time. The Jacobi preconditioner demonstrates robustness and reliability in the presence of fragmented flows. For a dambreak simulation, GPU speed ups demonstrate up to 10-18 times and 1.1-4.5 times compared to single-threaded and 16-threaded CPU run times respectively.
    Original languageEnglish
    Pages (from-to)81-103
    Number of pages23
    JournalComputer Physics Communications
    Volume226
    Early online date6 Feb 2018
    DOIs
    Publication statusPublished - May 2018

    Keywords

    • Incompressible SPH
    • GPU
    • free-surface flow simulation
    • DualSPHysics
    • ViennaCL

    Fingerprint

    Dive into the research topics of 'Incompressible SPH (ISPH) with fast Poisson solver on a GPU'. Together they form a unique fingerprint.

    Cite this