Co-Simulations Using AcuSolve

This section details the capabilities of AcuSolve in simulating the multi-physics problems by coupling with structural solvers.

Fluid Structure Interaction (FSI)

One of the rich features of AcuSolve lies in its ability to simulate FSI problems.

AcuSolve simulates these problems using two different technologies:
Practical FSI (P-FSI)
In P-FSI simulations, AcuSolve and the structural code are run separately. The Eigen solution obtained from a structural solver is projected onto the CFD mesh and used as boundary conditions to displace the fluid mesh. The mass, stiffness and damping arrays are also transferred from the structural model to flexible body in the CFD model, completing the inputs necessary to compute the structural deformation. P-FSI is preferred for simulations that have linear structural response (linear material properties and small mesh deformations).
Direct Coupled FSI (DC-FSI)
For applications involving a nonlinear structural response, AcuSolve is coupled at run time to a structural solver using the DC-FSI approach. The codes are run in tandem and exchange forces and displacements at each time step. This technique captures all nonlinearities in the structural model and can exploit the full capabilities of the structural solver. The DC-FSI technology within AcuSolve performs all projection and interpolation between the structural and CFD meshes without the use of any middleware. The supported structural solvers for AcuSolve include OptiStruct, Abaqus and MD-Nastran.

Coupled Multibody Dynamics (MBD) with AcuSolve

AcuSolve can be directly coupled with MotionSolve, a multibody dynamics solver, to solve multi-physics problems that involve both fluid and rigid body dynamics.

The wetted surfaces are paired with rigid bodies and loads. Displacements are exchanged during the run time using AcuSolve’s code coupling interface. The coupling is currently supported for rigid body motion only and not for a flexible body. However, AcuSolve supports both one way and two way coupling with MotionSolve. With one way coupling, the displacements are read from a file generated from MotionSolve and projected onto AcuSolve. With two way coupling, the codes exchange forces and displacement at each time step.