Am I essentially able to create any simulation for 3d models?

I want to use Unity for viewing 3d models, but I want to know how far I can go when it comes to testing them. Testing the airflow through the model, the temperature changes, material stress, etc. Can stuff like this be done?

Put simply, there’s no real reason why you can’t do any of that.

However, just because you can doesn’t make it any less involved than calculating realistic forces in any other program/scenario. The main thing Unity would be able to provide would be a (potentially) realtime, 3D representation of/for your testing environment.

It’s worth noting, however, that if the calculations are your main bottleneck, a .NET language (C#) would not be the “optimal” choice in terms of potential, raw computation/calculation speed.

Additionally, since Unity works primarily in 32-bit floating point values, you would potentially lack precision where you would need it in a true-to-life simulation (unless you’re calculating it yourself with greater accuracy, then just showing the closest approximations on screen, but then Unity isn’t vital to that approach either).