CFX setup question

dedicatestar · March 29, 2016, 15:14

Hi, I am doing an impeller rotating in tube, and the result is not as what I expected. My current setup is that I hold the impeller stationary, and rotating the fluid domain. As I increase the RPM and keep the pressure between the inlet and outlet constant, the mass flow rate at the outlet just doesn't change at all. This gives me and impression that the rotation has no influence at all. Can someone please help check my setup, and let me know if I did anything wrong?

Screen Shot 2016-03-29 at 2.09.36 PM.jpg

Screen Shot 2016-03-29 at 2.09.19 PM.jpg

Screen Shot 2016-03-29 at 2.08.49 PM.jpg

Screen Shot 2016-03-29 at 2.08.00 PM.jpg

ghorrocks · March 29, 2016, 21:10

You do not model the impeller as a solid for most cases. The impeller is a region removed from the mesh - you model the fluid region around the impeller.

Have a look at the meshes used in the CFX tutorial examples for what you need. Also have a look at how they set up this type of simulation.

March 29, 2016, 15:14	CFX setup question	#1
dedicatestar New Member Vanessa Wei Join Date: Mar 2016 Posts: 1 Rep Power: 0	Hi, I am doing an impeller rotating in tube, and the result is not as what I expected. My current setup is that I hold the impeller stationary, and rotating the fluid domain. As I increase the RPM and keep the pressure between the inlet and outlet constant, the mass flow rate at the outlet just doesn't change at all. This gives me and impression that the rotation has no influence at all. Can someone please help check my setup, and let me know if I did anything wrong? Screen Shot 2016-03-29 at 2.09.36 PM.jpg Screen Shot 2016-03-29 at 2.09.19 PM.jpg Screen Shot 2016-03-29 at 2.08.49 PM.jpg Screen Shot 2016-03-29 at 2.08.00 PM.jpg

March 29, 2016, 21:10		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,872 Rep Power: 144	You do not model the impeller as a solid for most cases. The impeller is a region removed from the mesh - you model the fluid region around the impeller. Have a look at the meshes used in the CFX tutorial examples for what you need. Also have a look at how they set up this type of simulation. dedicatestar likes this.

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