A Hybrid Parallelism Framework of SPH for the Applications in Automobile Gearbox
摘要
The rotating machineries of automobile, such as gears and motors, are involved with complicated interactions between fluids and structures, resulting in flow phenomenon such as free-surface, moving boundary, thermal conduction etc. Smoothed Particle Hydrodynamics (SPH), due to its Lagrangian nature, is preferred to simulate such phenomenon. The complexities of automobile structures require small particle distancing and therefore large number of particles are needed to discretize both fluid and structure. The small time step of SPH simulation is also required due to intense flow splashing resulting from high-speed moving boundary. Both two points above lead to large amount of computation during SPH simulation. In this paper, a parallelism framework of weakly compressible SPH(WCSPH) is proposed to accelerate SPH simulation by high-performance computing cluster. A hybrid parallelism strategy, with both Message Passing Interface (MPI) and Intel Threading Building Blocks (TBB), is used to reduce the total number of processes and therefore reduce the latency due to communication among computing clusters network. METIS is used to decompose the computational domain enabling dynamic domain decomposition and load balancing. The oil motion inside a gearbox is successfully simulated using the proposed framework, showing that the proposed parallelism framework is applicable to complex industry application and can accelerate SPH simulation efficiently.