swirl flow in FolwWork Simulation

linsir0825 · May 23, 2011, 07:20

Hi All

I have a question about the swirl flow setting.When I let the Fan inlet be a swirl flow,FlowWork Simulation will ask me to enter two value
1. Angular Velocity
2. Radial Velocity

Angular Velocity is the Fan rotation speed ????
And how to calulate the Radial Velocity ???

Boris_M · June 7, 2011, 06:02

Hi Larry,
if you define a swirl flow in a regular boundary condition your flow has three components, the axial (perpendicular to the inlet surface), the angular velocity which is the rotating speed (RPM or rad/s) as you can see from the units and the radial velocity is the velocity you have in radial direction in case the fan creates not a cylindrical flow but a cone like flow outwards like diagonal fans do.

For a regular "Fan curve"-Fan you have to set the angular velocity and the radial velocity as it is not defined in the fan data and the axial velocity is corresponding to the fan curve unlike for a regular boundary condition where there is not a fan curve related to.

For an "Axial Fan"-Fan from the database the angular velocity is defined in the database settings of the fan as rotating speed and the radial velocity is calculated from the inner and outer hub diameter which describe the two hub diameters on both sides of the fan. If they are not the same, you would define a diagonal fan if they are the same it is a straight blowing axial fan. So here these values are defined and calculated from the database.

I hope this helps,
Boris

May 23, 2011, 07:20	swirl flow in FolwWork Simulation	#1
linsir0825 New Member Larry Lin Join Date: May 2011 Posts: 2 Rep Power: 0	Hi All I have a question about the swirl flow setting.When I let the Fan inlet be a swirl flow,FlowWork Simulation will ask me to enter two value 1. Angular Velocity 2. Radial Velocity Angular Velocity is the Fan rotation speed ???? And how to calulate the Radial Velocity ???

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June 7, 2011, 06:02		#2
Boris_M Disabled Join Date: Jul 2009 Posts: 616 Rep Power: 24	Hi Larry, if you define a swirl flow in a regular boundary condition your flow has three components, the axial (perpendicular to the inlet surface), the angular velocity which is the rotating speed (RPM or rad/s) as you can see from the units and the radial velocity is the velocity you have in radial direction in case the fan creates not a cylindrical flow but a cone like flow outwards like diagonal fans do. For a regular "Fan curve"-Fan you have to set the angular velocity and the radial velocity as it is not defined in the fan data and the axial velocity is corresponding to the fan curve unlike for a regular boundary condition where there is not a fan curve related to. For an "Axial Fan"-Fan from the database the angular velocity is defined in the database settings of the fan as rotating speed and the radial velocity is calculated from the inner and outer hub diameter which describe the two hub diameters on both sides of the fan. If they are not the same, you would define a diagonal fan if they are the same it is a straight blowing axial fan. So here these values are defined and calculated from the database. I hope this helps, Boris