velocity components in cylindrical coordinates

iperten · March 31, 2009, 05:11

Dear all,

good morning.

I am simulating the flow within a vaned diffuser which is downstream of a radial impeller.

I want to calculate the flow angle alpha5 at the diffuser outlet (station 5 in my case): alpha5=tan(C_tang_5/C_rad_5), where C_tang and C_rad are the tangential and radial components of absolute velocity C, respectively.

At station 5 I can of course extrapolate C_5 in CFX-post by means of Tools --> Function calculator (and I usually calculate the mass flow averaged value). I can also find the velocity components of the absolute velocity in cartesian coordinates.

As you can see from above, in reality I am interested in the velocity components expressed in cylindrical coordinates: is there any method/way to find/calculate them?

Thanks a bunch.
Kind regards, Mattia.

Timon · March 31, 2009, 05:19

In post, go to the turbo tab. After defining the axis of rotation you can let post calculate the cylindrical components, which then appear as normal variables.

iperten · March 31, 2009, 09:22

Thank you!

It seems working!

Kind regards.

March 31, 2009, 05:11	velocity components in cylindrical coordinates	#1
iperten New Member Mattia Join Date: Mar 2009 Posts: 9 Rep Power: 17	Dear all, good morning. I am simulating the flow within a vaned diffuser which is downstream of a radial impeller. I want to calculate the flow angle alpha5 at the diffuser outlet (station 5 in my case): alpha5=tan(C_tang_5/C_rad_5), where C_tang and C_rad are the tangential and radial components of absolute velocity C, respectively. At station 5 I can of course extrapolate C_5 in CFX-post by means of Tools --> Function calculator (and I usually calculate the mass flow averaged value). I can also find the velocity components of the absolute velocity in cartesian coordinates. As you can see from above, in reality I am interested in the velocity components expressed in cylindrical coordinates: is there any method/way to find/calculate them? Thanks a bunch. Kind regards, Mattia.

March 31, 2009, 05:19		#2
Timon Member Join Date: Mar 2009 Posts: 44 Rep Power: 17	In post, go to the turbo tab. After defining the axis of rotation you can let post calculate the cylindrical components, which then appear as normal variables. njdyck likes this.

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March 31, 2009, 09:22		#3
iperten New Member Mattia Join Date: Mar 2009 Posts: 9 Rep Power: 17	Thank you! It seems working! Kind regards.