Good day!
We have a project here that uses a flexible pneumatic actuator in which we need to simulate in autodesk inventor v2013.
Is there anyway that we can do this? Is it possible to simulate an air pressure entering a cylinder and control it? Thank you very much…
Sure, using Autodesk CFD, I have done something similar while simulating spud guns however, it will take some work as CFD has a very steep learning curve 
Autodesk CFD? is it something like the Autocad 3D?
honestly, I am a noob with regards to autodesk inventor…
what I did was I have created a 3d model of a flexible pneumatic in autocad then imported it to autodesk inventor… What I was thinking is that I can simulate it directly in Autodesk Inventor but I do not know how. I have thought of creating an air compressor also in autocad then import it again to autodesk inventor but I don’t know how will I gonna input the air pressure that I want.
It’s in a different family of products: Simulation Software. CFD stands for computational fluid dynamics. Steep learning curve is an understatement.
Unless your model is a lot more complicated than the overview you gave, I’d recommend just doing the math and the using the result to set the motion in Inventor. (Look at Integrated Motion Simulation at the bottom).
If you’d like more guidance, it’s be helpful to know what you mean by “flexible pneumatic”. Are you taking about moving a piston within a cylinder? Or this this a pneumatic muscle? (Or is this something like putting air in a hose and determining the forces on it?)
the flexible pneumatic that I was saying is a flexible bending joint…
the bending of the flexible pneumatic will depend on the air pressure that will enter its air cavity.
Ah - I’ve never done anything with flexible pneumatic bending joints, but I’d venture if you’re looking to simulate something like a dexterous robotics hand, you’ll want CFD. You could probably fake it to an extent with a combination of exogenous calculations and Inventor motion simulation, but CFD would be the real deal. Someone else here may know a more elegant Inventor workaround, though. I also bet there’s a CFD forum out there, and even if you said you didn’t want to use CFD, people on it would probably know Inventor approaches pretty well. Best of luck 
What are you trying to learn from this? Why do you need to simulate air entering the pneumatic?
If you want to simulate the pneumatic at a certain position you can make a flexible pneumatic assembly, you can set up a dynamic simulation, or you can use positional representations. All of these are a million times easier than simulating air entering the pneumatic.