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Explore the powerful combination of TwinMesh application and Ansys Workbench CFX for advanced CFD simulations.

Using TwinMesh with Ansys Workbench CFX

TwinMesh is a powerful grid generation tool for many different types of pumps that typically works with stand-alone applications such as Ansys CFX.

An introduction to this tool with further details, and a sample 2D application can be found in the below link:

Introduction to TwinMesh

A design engineer may want to perform automated parametric analysis with a generated TwinMesh model. In order to achieve that, an Ansys Workbench application can be considered 

Tips for optimizing TwinMesh simulations in Ansys Workbench CFX for parametric analysis

After generating the TwinMesh model, the procedure to follow is summarized as follows:

1. Export all files from TwinMesh
2. Save the created setup in CFX Pre (def- or cfx-file)
3. Create a Workbench Project
4. Create a CFX Component
5. Right-click on the CFX cell to add the created def- or cfx-file including the TwinMesh setup
6. Open CFX Pre in Workbench
7. Copy the “grids” directory to a user location (from the current TwinMesh export).
8. Specify an absolute path for the grids folder (right-click on “User” in CFX Pre outline -> Edit in Command Editor -> change “MeshDir = ../grids” to an absolute path like “MeshDir = D:\MyProject\grids”)
9. Copy the “winnt-amd64” and “linux-amd64” directory to a user location (from the current TwinMesh export).
10. Specify an absolute path for the user Fortran routines (right-click on “User Routines” in CFX Pre outline -> Edit in Command Editor -> change “Library Path = ..” to an absolute path like “Library Path = D:\ MyProject”)
11. Create an input parameter in CFX Pre
12. Run the case
13. An Error is shown in Messages regarding User Routine directory definition (no problem)
14. All other cases should be initialized by initial conditions (Change “Initialization option” to “Update from initial conditions”). Otherwise, you have taken into account that the rotor position of the previous run fits to the zero position of the current run.
15. “Clear Execution Control” from the CFX Cell to prevent execution control conflicts in parametric study
16. Go ahead with creating an output parameter in CFD Post and all other parts of parametric definition

Sample application

An application with a 3D eccentric screw pump is demonstrated with the below video:

 

Post by Ertan Taskin
June 21, 2024