FAQ - smartFOAM solver user interface

**1. I am using smartcfd on windows. I do not see the solver running, what should I do?** **Ans:** smartcfd installation on windows offers two modes of execution. You can run the simulation locally or you can submit a simulation for remote execution over Linux based compute clusters. Please check Tools -> Remote Connection Settings and make sure that the Remote connection is disabled. Before starting the calculations, verify that you are able to get run.bat file created after using "Write Simulation Files" option under start simulation. ![enter image description here][1] ---------- **2. I am not able to load an existing project. Smartcfd says the project is opened by another session. How can I access my old project?** **Ans:** Once you load a project in smartcfd interface, it creates proj.lok file in working project area. This lok file prevents the user from accessing the same project via another smartcfd session. Once the session is closed, the lok file gets removed automatically. However, any crash or forceful kill of smartcfd will retain prj.lok file in the project area. Manual removal of the lok file will ensure that you can load the project in smartcfd application. ![enter image description here][2] ---------- **3. Which OpenFOAM version smartcfd is based on?** **Ans:** smartcfd-4.2 is based on OpenFOAM-2.2. ---------- **4. I have run the simulation up to 100 iterations. What do I need to do for restarting the simulation?** **Ans:** The default mode of smartcfd is restart. Hence, once you increase the end time, smartcfd will automatically start the simulation from the latest time directory present in your project area. Thus, once you have 100 as highest time directory and you write the Simulation files, the simulation should continue from 100 iterations. In case you wish to start from scratch, use “Clean All Results from Project Area” option in the Start simulation menu. ---------- **5. I am running VOF application; I do not see any phase being patched? What is missing?** **Ans:** The user can initialize the phase fraction based on fluid zone or regions created with smartcfd. The phase fraction value gets imposed only when Patch phase Fraction option is turned on. So please make sure that you enable this patch option before writing the simulation files. ![enter image description here][3] ---------- **6. It appears my initial conditions imposed via STL File based regions are not getting imposed? Why?** **Ans:** Stl file based initialization is available in smartcfd-4.X. In addition to the file name, the user also needs to specify an outside point location. This point location has to be outside the STL file but inside the computational domain. Once the point location is appropriate, the patching should work fine. ![enter image description here][4] ---------- **7. I see Ensight logo within smartcfd. How can I launch Ensight, FieldView and other applications from smartcfd?** **Ans:** smartcfd allows user to launch many applications via user interface. To achieve this, the user needs to set the correct path for the application of interest. It is controlled via: C:\Users\login.name\.SMARTCFD\.SMARTCFD-4.X\defaultCmdFile.csv file on Windows & ~/.SMARTCFD\.SMARTCFD-4.X\defaultCmdFile.csv file on Linux. The user can edit this file to specify correct path/application name of the software to be launched. ---------- **8. What will be recognized as acceptable mesh quality for OpenFOAM? How do I check that?** **Ans:** The user can perform checkMesh operation once Mesh file or polyMesh is imported. In general, any mesh with non Orthogonality less than 70 is recognized as acceptable. However there are many other parameters like aspect ratio, skewness, cell volume, Tet Quality, Cell determinant that need to be checked. A detailed report on mesh quality can be obtained by execution of following command: checkMesh - allGeometry ---------- **9. What is the interpenetration of three options that we have under Start Simulation.** **Ans:** Start Simulation allows many controls to the user to manage start of OpenFOAM based simulation. These are: 1. Write Simulation Files: Write OpenFOAM input files in current project area. 2. Start Simulation: Execute the run script (run.sh or run.bat) from the current project area. 3. Write Files and Start Simulation:Write simulation files and execute the run script. Cleanup Project Files: Removes all files in current working project area except: mesh/case, polyMesh and the .prj files. ![enter image description here][5] ---------- **10. How do I specify rotational velocity for a fluid zone?** **Ans:** Rotational Speed can be specified for Fluid zone under boundary conditions. Please make sure that you have enabled Moving Zones/MRF options from Flow Physics Tab and appropriate fluid zone is selected. The origin and axis of rotation need to be specified in addition to the value of rotational speed. The origin could be any point on the axis of rotation. A quick way is to update the origin is to right click on the fluid zone and use Update Origin option. The expected input for axis of rotation is a position vector. Its value can be obtained by using any two points (P1, P2) along the axis. The axis of rotation will then be P2-P1. The direction of rotation is calculated by right hand thumb rule. ![enter image description here][6] ---------- **11. I am not able to see in any fluid zone after reading polyMesh? Is that acceptable?** **Ans:** OpenFOAM does not expect fluid zone for simulation. Fluid zones are required only for additional physics specifications such as Multiple Reference Frame, Porous Zone, Sliding Mesh, etc... ---------- **12. Which file do I need to load in paraview to see my simulation results?** **Ans:** Paraview accepts files in different formats. You can export results in the form of VTK or Ensignt Files and load them in Paraview. However, the easiest option is to load project-name.foam file in Paraview. The .foam file gets automatically loaded once you launch Paraview within smartcfd interface. ---------- **13. Do I need to leave the interface open while simulation is running?** **Ans:** No. There is no need to keep the interface open while the simulation is running. You can exit smartcfd via File Exit option. You should be able to reconnect to a working session after reloading the project. However, in case the compute machine gets shutdown the simulation will get killed. ---------- **14. As I start iterating, I get bounding of k, epsilon variables immediately. What should I do?** **Ans:** Bounding is observed in the solver, when solution variable shoots to unrealistic high or low values. In many cases it is observed that bounding disappears as the solution progresses. In case bounding for turbulence parameters persists, the user needs to verify initial and boundary conditions for epsilon. ---------- **15. I need to share the project with a colleague/smartcfd team. Which files should I send?** **Ans:** The project file is the one that you need to share with your colleague. It contains all details for the solver setup. In addition, your starting point for the project in terms of mesh/case or polyMesh is required as well. [1]: http://www.tridiagonal.com/images/Tridiagonal.Solutions/p1-remote [2]: http://www.tridiagonal.com/images/Tridiagonal.Solutions/p2-files [3]: http://www.tridiagonal.com/images/Tridiagonal.Solutions/p3-patch [4]: http://www.tridiagonal.com/images/Tridiagonal.Solutions/p4-init [5]: http://www.tridiagonal.com/images/Tridiagonal.Solutions/p5-options [6]: http://www.tridiagonal.com/images/Tridiagonal.Solutions/p6-mrf
Published on: 2014-03-20 See other articles in smartcfd.