ansys mechanical 1

[Jose Antonio]

dear friends Im making a transient thermal simulation with ansys mechanical and it sends me an error. it says THE MEMORY SIZE REQUESTED IS NOT CURRENTLY AVAILABLE, REENTER ANSYS COMAND LINE WITH LESS MEMORY REQUESTED. what do you think this means. Im modeling a solid ring of 6 meters diameter and with coarser mesh I get a soluton but when a refine the mesh it brings me this error. anyone knows please

 

[hendersdc]

It probably means that your mesh is too big for your computer to handle. Some things you can try to have a finer mesh and still be able to run:

- Reduce the size of your bounding box for the analysis to the minimum needed
- Take advantage of any symmetry your problem may offer and only analyze 1/2, 1/4 or 2D axisymmetric model (if your problem is axisymmetric this would be by far the biggest improvement you can make to reduce your run time and mesh size)
- Only refine the mesh where absolutely needed and leave it coarse where possible
- Simplify the geometry, getting rid of any very small features that shouldn't affect the result but are driving up the size of your mesh
- Get a computer with more memory

 

[Jose Antonio]

thanks hendersdc I would try those things if my computer is short in capabilities what its happening to me is I think a bad configuration of the ansys mechanical, I dont know how to work with the -db size and the -m size, because in the software help tells that I need to change this values if mi model is going to be large. The older user of ansys should know how to modify this in favor of the simulation, there are several fails in the software if I dont know how to vary this values.

 

[Jose Antonio]

does anyone know how to configure the Mechanical for larger models (1 million cells and up)

 

[L_K]

What are the specs of your computer? Have you changed changed any of the solve process settings manually
before solving?

 

[Jose Antonio]

I have 10 gb of ram, 8core i7 processor and nvidia quadro gcard, but my problem is that I make simulations with few elements mesh and it works and when I put some finer mesh of more elements it doesnt finish the solving process or it tells me that there is a lack of memory, and I dont know how to change de database memory or the memory workspace in favor of the larger simulations

 

[Jose Antonio]

L_K what should I change to do the solving process better

 

[L_K]

Just wanted to check that you have tried with the default settings until now. Putting random values there
might just cause more problems. Maybe you could decrease element size in smaller increments and see if the
results you are interested in change in the model (mesh convergence).

 

[Jose Antonio]

yes thats what Im doing until one light tells me how to make finer meshes or how to check when the results are independent of the mesh just like in fluent, do you know something about this

 

[L_K]

Procedure should be the same than in Fluent. Many times the most interesting result
is the maximum temperature. Calculate the relative change between models (I think there
is no general number for this so engineering judgment is needed, maybe max. 5%).
Also, you can parametrize the mesh size and the result if you want to do a parametric study.