GPU-Accelerated Simulations of Problems with Moving Boundaries and Fluid-Structure Interaction at Extreme Scales

TL;DR

This paper introduces a GPU-accelerated implementation of the immersed boundary method for fluid-structure interaction simulations involving complex moving bodies, achieving significant speedups and scalability on large-scale problems.

Contribution

The work presents a GPU-optimized, scalable implementation of the immersed boundary method using CUDA and MPI, enabling efficient simulations of large and complex fluid-structure interactions.

Findings

Achieved 20x speedup over CPU implementations.

Demonstrated >90% scaling efficiency on multi-GPU setups.

Successfully simulated turbulent flow and bat wing flight at Re=5000.

Abstract

Computational fluid dynamics and fluid-structure interaction simulations involving moving and deforming bodies is extremely hard. In this work, we present a graphical processing unit (GPU) optimized implementation of the sharp-interface immersed boundary method. The method allows performing simulation around complex stationary as well as moving bodies on a Cartesian grid. We base our implementation on the ViCar3D framework and make use of OpenACC, CUDA, NCCL and MPI. We test the implementation across grid sizes ranging from O(10million) to O(1billion) points and achieved a 20X speedup compared to existing CPU implementation. We next present our multi-GPU implementation by utilizing CUDA streams and NCCL communicators. This enables us to obtain a >90% strong and weak scaling efficiencies. Next we demonstrate the capability of the developed software to simulate a turbulent fluid flow and coupled fluid-structure interaction in flapping bat wing in flight at Re=5000.