## Ansys Free Student Software

#### Save a project in an earlier version

• Babeth
Subscriber

Hello !

I don't know if it's the right place for this question, but I didn't know where to post it.

I have a free 2021R1 version in my laptop, and I have done all my project with it. But as my computer is not powerful enough (calculation time is huge), I need to run my project on a more powerful computer in my laboratory. But this computer has a 2020R2 version. So can I just save all my project in an earlier version using the workbench ?

Regards,

Elisabeth

• peteroznewman
Subscriber
Unfortunately, there is no easy way to save a project to an earlier version. You have to build the model from scratch, sorry.
Are you using Explicit Dynamics? That calculates a time step that can be tiny and result in long solution times. For example, if the solver estimates that it will take 300 hours on your laptop because the time step is 1e-7 seconds, that same time step will be present on the lab computer. What is the clock speed of your laptop? You will find the lab computer clock speed is not going to be much faster than your laptop (it may even be slower), it is certainly unlikely to be twice as fast and even if it was, that is still 150 hours of solution time, which is intolerable.
What you need to do is make changes to the model to increase the time step from 1e-7 to 1e-6. then the model will take only 30 hours on the laptop computer.
Here are some changes you can make to your Explicit Dynamics model to make it solve in less time. You can edit the density of the material to artificially reduce the time it takes to solve. For example, if you multiply the density by a factor of 25, the solution will take 1/5 of the time to compute the solution.
Another change is to increase the minimum element size. Look at the Mesh Metric called Characteristic Length. If you can increase the minimum length by a factor of 4, the solution will compute in 1/4 of the time.
If you do both those things, the solution will take 1/20 of the time to compute. Now that 300 hours becomes 15 hours on the laptop, which is tolerable.
None of the above applies to Transient Structural models, which use a completely different solver.
• Rob
Ansys Employee
Just to add to comments. The Workbench session can't be saved in an earlier version. However, some of the solver files may be exported and read into an older version: it's not recommended and you will need to check all the settings but it may be possible. Check what export options you have in the solver and see how you get on.
Doing it again will be safer, probably easier and good practice with the software.
• Babeth
Subscriber
Yes I'm working on Explicit Dynamic.
The main problem is that my geometry is relatively complex... I'll try to just import the .scdoc from my version to the 2020 version, I hope this works. The clock speed of my computer is 2GHz, and my computer has just an i3 processor, whereas the lab computer has an i7 or i9... Also, I think that a change of the density will distort my results... but I'll try to increase the time step and to decrease the number of elements.
Thank a lot Regards Elisabeth
• Rob
Ansys Employee
If scdoc fails to transfer the Step (stp) format will pass across as its generic. I'm not sure that's available in Student though. If not, you may need to install a newer build on the lab computer.
• peteroznewman
Subscriber
Yes, high density can alter the results. The idea is if you need to run to model many times to find many mistakes, you find the mistakes much faster. Once all the mistakes have been found, you set the density back to normal and wait the longer time for results, then you can see the effect of the high density by comparing with the previous, mistake-free solution.