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## Simulation CFD

Member
Posts: 6
Registered: ‎02-25-2014

# Moment of inertia in flow driven angular motion

177 Views, 3 Replies
03-13-2014 06:08 PM

I have a simulation that I need to use flow driven angular motion for a turbine blade. However, I cannot find where I should enter the moment inertia of turbine? I went through tutorial but it's not there. Can anybody help?

Product Support
Posts: 725
Registered: ‎08-25-2011

# Re: Moment of inertia in flow driven angular motion

03-14-2014 01:15 AM in reply to: l.mahmoudi

You would need to use a Rotating Region (best way to simulate rotating motion, rather than just motion).

There is a guide for this here: Centrifugal Pumps and Axial Fans

Jon Wilde
Member
Posts: 6
Registered: ‎02-25-2014

# Re: Moment of inertia in flow driven angular motion

03-14-2014 07:53 PM in reply to: wildej

Jon,

I've read the manual about rotating region but I cannot use the rotating region since I have a stator right after the rotor with the exact geometry and both of them are placed in a pipe. I've attached a picture for more clarification(the pipe is not shown).Based on the rotating region guidelines, it shouldn't touch any solid part so I cannot use this method. The only method that I can use is the angular motion. However, in neither of methods there is no place to enter the moment of inertia? can you clarify this?

Product Support
Posts: 290
Registered: ‎08-31-2011

# Re: Moment of inertia in flow driven angular motion

03-20-2014 08:02 AM in reply to: l.mahmoudi

Any flow driven motion does not require moment of inertia. This is dictated by the material and the geometry.

Rotating regions have this as an input because techncially you can suppress the solid at which point the rotating region would need information about the inertia.

Rotating regions can be done around portions even if there is a stator nearby. Care must be taken such that the region only encompasses what spins.

That being said, this is all covered in the Help. Under Motion we do discuss the interia items as well as how this would apply with Rotating Regions