Inlet boundary condition of swirl angle

tjliang · June 30, 2016, 17:01

Dear Openfoamers,

I want to simulate a jet flow which has a swirl angle of 45 degree at inlet. How can i define this bc?

Best regards ,

Peng

TobM · July 1, 2016, 05:01

What about this bc here:
swirlFlowRateInletVelocity

http://openfoam.github.io/Documentat...ml/a02600.html

this should do what you want. You have to calculate the flow rate and rpm so that you get a 45 degree swirl angle.

tjliang · July 1, 2016, 06:06

Quote:

Originally Posted by TobM

What about this bc here:
swirlFlowRateInletVelocity

http://openfoam.github.io/Documentat...ml/a02600.html

this should do what you want. You have to calculate the flow rate and rpm so that you get a 45 degree swirl angle.

Thanks, but could you please tell me more about the relation between rpm and swirl angle?

TobM · July 1, 2016, 06:56

"This boundary condition provides a volumetric- OR mass-flow normal vector boundary condition by its magnitude as an integral over its area with a swirl component determined by the angular speed, given in revolutions per minute (RPM)"

As I understand it:
Mass or volumetric flow define the normal velocity component and rpm the rotational. You have to calculate the exact values you need according to your problem.

June 30, 2016, 17:01	Inlet boundary condition of swirl angle	#1
tjliang Member Peng Liang Join Date: Mar 2014 Posts: 60 Rep Power: 12	Dear Openfoamers, I want to simulate a jet flow which has a swirl angle of 45 degree at inlet. How can i define this bc? Best regards , Peng

July 1, 2016, 05:01		#2
TobM Member Join Date: Sep 2014 Location: Germany Posts: 88 Rep Power: 12	What about this bc here: swirlFlowRateInletVelocity http://openfoam.github.io/Documentat...ml/a02600.html this should do what you want. You have to calculate the flow rate and rpm so that you get a 45 degree swirl angle. gio3 likes this.

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July 1, 2016, 06:56		#4
TobM Member Join Date: Sep 2014 Location: Germany Posts: 88 Rep Power: 12	"This boundary condition provides a volumetric- OR mass-flow normal vector boundary condition by its magnitude as an integral over its area with a swirl component determined by the angular speed, given in revolutions per minute (RPM)" As I understand it: Mass or volumetric flow define the normal velocity component and rpm the rotational. You have to calculate the exact values you need according to your problem.