Hi want t ask i run the simulation but then it went to problem and i dont understand what it says. Can someone help me with this problem so that i can run it. initially i run with a circular pattern fi, it works well but when i change to square pattern fin it cannot run. Thank you very much for the help.
link to my project
Hi, welcome to SimScale and to the Forum!
Thanks for posting here. This error normally arises because of some instability at the start of the simulation. It indicates that the temperature result field has diverged.
The fist thing that I would check is the mesh. The mesh quality look to be OK.
The second thing to check is look at where the result is diverging. This will give you an idea of what might be causing the instability. You can check this by opening the Solution Field and looking for the diverged (very high or very low temperatures) temperature region. To do this you can create an Iso Volume that highlights the regions. In your case it is very low unexpected temperatures.
In this case the flow domain is diverging near to the fins, in the boundary layer cells or the next cells.
These indications suggest that you need to further refine your mesh. I would try a fineness on the slider of 7 or 8. You could also try increasing the number of boundary layers.
thank you so much for the reply Sir. Really appreciate it. Definitely will try these suggestion
Hi,
Looking at this again I realised that you are using the older version of the “Conjugate Heat Transfer” solver. I would recommend using “Conjugate Heat Transfer V2” for this case. It is more stable and Conjugate Heat Transfer will be phased out of SimScale soon.
I started a new run here with Conjugate Heat Transfer V2. Just make sure that the boundary conditions etc. are equivalent to what you had defined in your original run.
Steve
Ooh I see, noted with thanks Sir. Definitely will try the CHT version 2. Thanks for the infomation Sir, really appreaciate it.
Maybe there is another issue as the CHT V2 simulation that I started experienced the same problem.
Oh no how we tackle that problem sir. My Computational Hours also only 100 hours left. I need to fully utilize the remaining hours.
I took another look at the CAD. There are small features on the fins that will require a fine mesh to correctly resolve them. I would recommend a simplification of the fins so that they are flat. Otherwise you will need a very fine mesh to resolve the surface of the square fins.
Hi @bk19110254 , I ran your geometry with the new Immersed Boundary solver. It creates a cartesian mesh, and therefore it is very stable and fast. You can find my simulation here. I applied the symmetry boundary condition as an adiabatic and no-slip wall for the solids and an adiabatic, slip wall for the fluid. In your simulation you defined the wall of the solar PV also as a heat source. I defined the heat source in my project a little differently. I calculated the total power by measuring the area and multiplying it the heat flux (1100) you provided. This amounted to a total power of 336 W which I applied as absolute power source (found in Advanced Concepts). You can find more information on the Immersed Boundary Method in SimScale here: https://www.simscale.com/docs/analysis-types/immersed-boundary-analysis/
Here are some images from the simulation run:
Thank you so much Sir for your help. i really2 appreaciate it for effort and time
Great info thanks!
