Plenary Speaker

Innovative Simulation for Multiphase Flows and Fluid-structure Interactions

Takayuki AOKI

Professor Aoki has been working on computational fluid dynamics and High-performance computing for 25 years. Since 2009, he has been a deputy director of Global Scientific Information and Computing Center (GSIC) in Tokyo Institute of Technology, which is famous as a world leading supercomputing center for GPU computing. He has been a pioneer of GPU applications and first-time publishing GPU programming (CUDA) textbook in Japan. His team succeeded in a phase field simulation using 330 billon mesh on 4,000 GPUs and awarded as Gordon Bell Prize in 2011.
In addition to multiphase flow simulation, he is interested in sport aerodynamics and photo-realistic visualization of CFD results with computer graphics technique.

Abstract

Simulations for gas-liquid two-phase flows and fluid-structure interactions are challenging topics in CFD, since the shapes of gas-liquid interfaces and solid surfaces are dynamically changing in time and space. We have developed two incompressible CFD codes based on weakly compressible schemes with Finite Volume Method and Lattice Boltzmann Method. The sound speed is artificially reduced and we accept a small compression within small velocity divergences. In addition, an AMR (Adaptive Mesh Refinement) method is employed to improve the computational efficiency drastically by assigning high-resolution mesh around moving interfaces. We have successfully implemented the octree-based AMR for GPU supercomputers and a dynamic domain partitioning to maintain the computational load balance. We demonstrate several applications: free swimming of dolphin/water strider, violent flag fluttering, debris flows including rocks and driftwoods and liquid films.