A scalable framework for the partitioned solution of fluid–structure interaction problems

Abstract

In this work, we present a scalable and efficient parallel solver for the partitioned solution of fluid-structure interaction problems through multi-code coupling. Two instances of an in-house parallel software, Ter-moFluids, are used to solve the fluid and the structural sub-problems, coupled together on the interface via the preCICE coupling library. For fluid flow, the Arbitrary Lagrangian-Eulerian form of the Navier-Stokes equations is solved on an unstructured conforming grid using a second-order finitevolume discretization. A parallel dynamic mesh method for unstructured meshes is used to track the moving boundary. For the structural problem, the nonlinear elastodynamics equations are solved on an unstructured grid using a second-order finite-volume method. A semi-implicit FSI coupling method is used which segregates the fluid pressure term and couples it strongly to the structure, while the remaining fluid terms and the geometrical nonlinearities are only loosely coupled. A robust and advanced multivector quasi-Newton method is used for the coupling iterations between the solvers. Both the fluid and the structural solver use distributed-memory parallelism. The intra-solver communication required for data update in the solution process is carried out using non-blocking point-to-point communicators. The inter-code communication is fully parallel and point-to-point, avoiding any central communication unit. Inside each single-physics solver, the load is balanced by dividing the computational domain into fairly equal blocks for each process. Additionally, a load balancing model is used at the inter-code level to minimize the overall idle time of the processes. Two strating the accuracy and computational efficiency of the coupled solver. Strong scalability test results show a parallel efficiency of 83% on 10,080 CPU cores.

A GPU Accelerated Framework for Partitioned Solution of Fluid-Structure Interaction Problems

“…These schemes conserve the mass, momentum and kinetic energy of the flow at the discrete level which is crucial in turbulent flow simulations [8,9]. For more details please consult [4].…”

“…The momentum equation is integrated on the undeformed configuration. More details concerning the governing equations and numerical methods for this solver can be found in [4].…”

“…In addition, we compare the simulation time with and without using GPUs for both the fluid solver and the overall coupled simulation. The essential parts of the current solver for the accuracy of the results are the same as those in [4]. Therefore, we do not provide any accuracy analysis in this work and focus only on the performance perspectives.…”

“…The solver is shown to scale well on 1,536 cores for a coupled FSI problem. Naseri et al [4] developed a scalable and efficient simulation environment for the partitioned solution of FSI problems. This framework employed two instances of TermoFluids [5] to solve the fluid and the solid problem and the preCICE coupling library [6] to handle inter-solver data communication, boundary data mapping and equation coupling.…”

“…In the current study, we extend the solver presented in [4], to exploit hybrid architectures (CPU-GPU) efficiently. A coupling strategy is incorporated that allows using GPUs to accelerate the expensive kernels of our FSI coupling procedure, minimizing the total run-time while preserving the simulation accuracy.…”