Fluids

Fluids

Error by creating automatic export in calculation activities

    • CFDaniel
      Subscriber

      Hello all,


      i'm doing the following tutorial which i found on youtube: FLUENT SIMULATION OF PCM IN REFRIGERATOR || SOLIDIFICATION AND MELTING ( 


      At 03:00 when creating the calculation activities i get the following error:


      Error: GENERAL-CAR-CDR: invalid argument [1]: improper list


       


      Error Object: global


       


      I choose CDAT for CFD-Post & EnSlight. When i run the simulation everything works fine, no divergence.


       


      Does anyone know what i'm doing wrong?


       


      Kind regards


      CFDaniel

    • Rob
      Ansys Employee

      A CAR-CDR error usually means there's a setting missing somewhere. Given the model runs OK, check the execute commands and whether Fluent is spitting out data. 

    • CFDaniel
      Subscriber

      Thank you rwoolhou.


      I think there is something wrong with the modeling of the PCM.


      When creating a contour plot with the liquid fraction of the PCM there is only 0 and 1.


      But when creating a contour plot with the temperature, it shows me a realistic temperature field.


       


      But i don't know what i did wrong with the modeling of the PCM, i followed all the steps several times and it makes everything sense to me

    • Rob
      Ansys Employee

      Does the PCM occupy the whole volume? Check liquidus & solidus temperatures: are they the same?

    • CFDaniel
      Subscriber

      The simulation is a 2D axisymmetric simulation and the PCM occupys the three little rectangles on the left side which is also the midline.


      Liquidus temperature is 274K


      Solidus temperature is 271K

    • Rob
      Ansys Employee

      How much mesh is there in those regions? 

    • CFDaniel
      Subscriber

      In General:


       


      Mesh Quality:


       


      Minimum Orthogonal Quality = 9.99966e-01 cell 14254 on zone 22 (ID: 25804 on partition: 2) at location ( 2.45466e-01 3.09200e-01)


      (To improve Orthogonal quality , use "Inverse Orthogonal Quality" in Fluent Meshing,


      where Inverse Orthogonal Quality = 1 - Orthogonal Quality)


       


       


      Maximum Aspect Ratio = 2.17979e+00 cell 1445 on zone 23 (ID: 42601 on partition: 0) at location ( 2.49484e-01 5.39000e-01)


       


      There are 2700 faces in each of the small rectangle and 3600 faces in the largest PCM surface.

    • Rob
      Ansys Employee

      Plot temperature with node values off, and also see what happens if you reduce the time step: you could be melting the material too quickly. 

    • CFDaniel
      Subscriber

      There is no big difference by plotting the temperature wit node values off.


      Reducing the time step doesn't change the result.


      If i plot the volume integral of liquid fraction over flow time, the liquid fraction increases.

    • DrAmine
      Ansys Employee

      Can you please add screenshots of solidification panel, temperature contours and Liquidus fraction contours?

    • DrAmine
      Ansys Employee

      Please try again uploading the images (via insert Image). As ANSYS Employee I do not download any attachments or go to any external site to download them there.


       


      The solidification and melting panel: The settings applied there.

    • CFDaniel
      Subscriber

      Everytime i upload an image via Browse i got an error: Sorry an error occured...


      Do you know what could be wrong with that?

    • DrAmine
      Ansys Employee

      I will check that. Probably we are experiencing some issues.

    • CFDaniel
      Subscriber

      Chrome and Edge doesn't work...

    • Rob
      Ansys Employee

      It's us: IT are working on it..... 


       

    • DrAmine
      Ansys Employee

      Can you try now inserting the screenshots?

    • CFDaniel
      Subscriber

      Solidifiaction and Melting Panel


      Liquid Fraction


      Temperature


      Now it is working. Thanks

    • DrAmine
      Ansys Employee

      Is is axissymmetric? Is the x-axis the axis of symmetry?

    • DrAmine
      Ansys Employee

      Is it expected that the PCM solid regions will start melting? Have you run for longer time?

    • CFDaniel
      Subscriber

      The model is axissymmetric and the y-axis is the axis of symmetry.


      It is expected that the PCM solid regions melts. I also run for longer time, but no difference.


      Here you can see the temperature field at t=0s.


      Temperature field at t=0s

    • DrAmine
      Ansys Employee

      Axis of symmetry has to be the x-axis.

    • CFDaniel
      Subscriber

      Sorry for the late response, i was in vacation.


      I looked through the simulation and made a mistake last time. The simulation isn't axissymmetric but the left side is the symmetry line. I got it mixed up.


      Do you know what else can be a possible error?

    • Rob
      Ansys Employee

      If it's 2d all that will do is mirror on that line. 

    • DrAmine
      Ansys Employee

      For 2d axis-symmetric  cases  the x-axis has to be the axis of symmetry (otherwise fluxes and field might be wrong). So make the vertical axis the x-axis by flipping the whole by -90°. If your case is not axis-symmetric just use 2D planar.

    • CFDaniel
      Subscriber

      @rwoolhou


      what do you exactly mean?


      @abenhadj


      my case is not axissymmetric. i use 2d planar and the whole left side of my geometry is a symmetry boundary.

    • Rob
      Ansys Employee

      Symmetry is effectively a mirror plane. As it's 2d (and no axisymmetric) it means you're effectively solving half of a cuboid shape. 

    • CFDaniel
      Subscriber

      Yes, that's the way i run the simulation. But i get the resuts shown above...

    • DrAmine
      Ansys Employee

      Something is completely wrong with your case either material properties or boundaries. As you are referring to that tutorial video, have you contacted the author of the video, perhaps he can provide you with this case.

    • CFDaniel
      Subscriber

      I have already contacted the author of the video but he didn't know this error and furthermore can't help me.


      Is it possible that someone of you can follow the steps through the tutorial and see if it works?

    • Rob
      Ansys Employee

      I've used the model fairly recently and it was working fine.  Start at the beginning and work through the whole model set up, boundary conditions, materials etc.  Double check there's a wall-wall:shadow pair between the different fluids zones if they're non-mixing. 

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