Zusammenfassung
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, TermoFluids, 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 finite-volume 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 multi-vector 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 practical test cases in the context of hemodynamics
are studied, demonstrating the accuracy and computational efficiency of the
coupled solver. Strong scalability test results show a parallel efficiency of
83\% on 10,080 CPU cores.
Nutzer
