## Fluids

Topics relate to Fluent, CFX, Turbogrid and more

#### [CFX][Setup] Cyl. Vel. Components

• betteroden
Subscriber

I have 3 inlet fans spinning at 1500 RPM ( =25 Rounds Per Seconds )

Pushing 250 [m^3/h] { 250/(60*60) *1.204 ~ 0.084 kg/s }

"1.204 is the air dencity at 20 degrees C"

I have 3 Coordinate systems, one for each fan!

I just want to understand what values are required for:

Axial component

Theta Component

Is axial the velocity of the outer edge of the fan?

Theta is radians per second for the outer edge of the fan?

• betteroden
Subscriber
Also what isninlet 1.1ninlet 1.2ninlet 1.3nis it:ninlet 1.1 = xninlet 1.2 = yninlet 1.3 = zn
• DrAmine
Ansys Employee
If you have already defined your local coordinate systems why not directly using them in the boundary specification?n
• betteroden
Subscriber

If you have already defined your local coordinate systems why not directly using them in the boundary specification?https://forum.ansys.com/discussion/comment/98365#Comment_98365

No idea what you mean !nI want to know:nn' Axial componentnRadial ComponentnTheta ComponentnIs axial the velocity of the outer edge of the fan?nRadial should be 0nTheta is radians per second for the outer edge of the fan? 'nnandnn' Also what isninlet 1.1ninlet 1.2ninlet 1.3nis it:ninlet 1.1 = xninlet 1.2 = yninlet 1.3 = z 'nnEdit*nI can not find a single place on the internet that talks about those! n
• DrAmine
Ansys Employee
1.3 will correspond to the local z axis. So that will be your local axis of rotation.n
• betteroden
Subscriber

1.3 will correspond to the "local z" axis. So that will be your local axis of rotation.https://forum.ansys.com/discussion/comment/98399#Comment_98399

thank you, now I have one question answered !nOne to go!n
• betteroden
Subscriber
Bump n
• DrAmine
Ansys Employee
Theta Velocity Component is the velocity component in circumferential direction and this is meter per second: Velocity dimension.n
• betteroden
Subscriber

Theta Velocity Component is the velocity component in circumferential direction and this is meter per second: Velocity dimension.https://forum.ansys.com/discussion/comment/98558#Comment_98558

that's the Axial component! nif not then the axial and theta is the same!!!n
• DrAmine
Ansys Employee

https://forum.ansys.com/discussion/comment/98558#Comment_98558that's the Axial component! if not then the axial and theta is the same!!!https://forum.ansys.com/discussion/comment/98858#Comment_98858

?n