SimScale CAE Forum

Actuator disk model for a ventilation fan

A recent post (Simulation of an Actuator Disk) [Simulation of an Actuator Disk] demonstrated how fluid momentum could be added to flow using a disc. However, this was a solid disc which would not work for a ventilation fan that spans the width of the flow channel (duct) and is the only momentum source in the system.

Would it be possible to use a porous disk? [Ref: https://www.simscale.com/projects/ROHIT_SR/porous/]. With a sufficiently high porosity, the pressure drop could be low and the momentum could still be added to the disk’s surface. Ideally this would induce negative pressure upstream and positive pressure downstream as it should in momentum theory [https://en.wikipedia.org/wiki/Momentum_theory].

Has anyone done this, or know if this would work? Or is there another approach?

Thanks everyone for your help!

Great project Doug!

Tagging @Retsam and @DaleKramer here - afaik Andrzej (@Retsam) has already worked with that and can give you some hints. If not I will jump back in :slight_smile:

Best,

Jousef

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Thanks Jousef. I really appreciate your help on this project.

@ROHIT_SR, @DaleKramer & @Retsam - any input from your side here? Will have a look at your project at some point Doug - I have a lot of requests at the moment :slight_smile: Hopefully one of the three can jump in here!

By the way, could you specify why you would want to simulate that? Which application do you want to use that for?

Best,

Jousef

I’ll be modelling ventilation systems with various size duct fans. First would simply be a 4" duct fan in a 4" duct, then 6", 8", etc. as needed. The upstream and downstream pressure distribution will be important so I’m hoping this will be present after the momentum as added at the fan. Thanks again.

Sorry guys: I have no idea how @dugclaws will try to simulate that concept of adding a momentum to a flow with rotating disk. Even less with porous disk (perhaps with disk having rough surface?). Momentum theory will not help here, in my opinion.

So I wait on @dugclaws simulation and possibly will comment later on.

Cheers,

Retsam

Thank you Retsam. I’ll try some different approaches and let you know how it works out :slightly_smiling_face: