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-   -   Free rotation of a swirler in a CC (https://www.cfd-online.com/Forums/cfx/23217-free-rotation-swirler-cc.html)

Maria Angelica October 26, 2006 12:19

Free rotation of a swirler in a CC
 
Hello!! I will start the simulation of a Combustion Chamber! It has a swriler for the inlet of the stechiometric air in the liner. I wonder how to set the motion in the swirler depending on the inlet velocity of the flow. Usually we can assign the rotation of the rotor, etc in other cases, but in this case, I want it to react to the forces of the flow!!

Does somebody know if this is possible! Any suggestions please!!!

Ma Angelica

Robin October 27, 2006 09:15

Re: Free rotation of a swirler in a CC
 
Hi Angelica,

If it is reacting to a torque on the swirler blades, write an expression for rotational velocity as a function of the blade torque. The general expression structure for torque is:

[<Fluid>.]torque_[<Axis>[_<Coord Frame>] ]()@<Location>

Say the blade region is called 'swirler blade', torque about the global x axis would be:

torque_x()@swirler blade

I would recommend putting an upper limit on the rotation rate to prevent it from becoming too high. If you write an expression for the swirler speed, say 'RPM Swirler', I would enter it in the rotational velocity parameter within a min function, i.e.:

min(RPM Swirler, Max RPM)

When using CFX, just keep in mind that just about anywhere you enter a value, you can also use an expression and CEL is evaluated on the fly.

Regards,
Robin

Robin October 27, 2006 09:16

Re: Free rotation of a swirler in a CC
 
Looks like the HTML formatting screwed up the expression structure I listed at the top of my message. Just look in the CFX Post documentation for this. The torque expression is correct.

María Angélica October 28, 2006 09:44

Re: Free rotation of a swirler in a CC
 
Thank you Robin!

I will try that!

Best Regards,

Ma Angelica


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