File-Based Coupling (through Imported CAE Model)

File-based coupling is a method used to couple Simcenter STAR-CCM+ with another CAE code via external files stored in the computer memory.

The method allows you to obtain a solution using separate CAE codes to solve for each part of the model, such as the fluid and solid domains in an FSI problem. The powerful set of tools available in Simcenter STAR-CCM+ allow you to import a CAE model into Simcenter STAR-CCM+ and carry out a one-way or two-way coupled simulation.

For one-way coupling, solution data from Simcenter STAR-CCM+ can be mapped onto the CAE model and exported in a format that can be read into the third-party application. The exported data can then be used to specify boundary or operating conditions in the CAE model. An example of this is using Simcenter STAR-CCM+ to compute the conjugate heat transfer solution in the fluid and solid domains of a model, then exporting the solid region temperature solution to an external file. This file can then be read into a third party code, and used to calculate the thermal stresses in the solid. An example of the typical workflow for one-way coupling is shown in the diagram below (solid blue arrows).

For two-way coupling, you can continue by importing solution data from the third-party code into Simcenter STAR-CCM+. This data can then be mapped onto the Simcenter STAR-CCM+ model and used to define a boundary condition in the simulation, or to update the mesh. An example of two-way coupling is using Simcenter STAR-CCM+ to compute the pressure and wall shear stress at a fluid-solid interface, using this data to define a traction load on the FSI surface in the CAE model, and calculating the resulting displacements using the third-party code. The nodal displacements in the solid model can be imported into Simcenter STAR-CCM+ and used as an input to the mesh morpher. The Simcenter STAR-CCM+ simulation can then be run using the updated geometry, and the whole process can be repeated until the solution has converged. The typical workflow for two-way coupling is an extension of that for one-way coupling. The additional steps for two-way coupling are shown in the diagram below (dashed gray arrows).