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 krisipanikou December 12, 2012 17:36

rotation

Hello,
I am trying to simulate heat transfer in a natural convection problem. My cylinder can is on a rotating disc.. I don't get the results I want, so I am asking you: Do I have to use the Frame Motion option from Cell Zone Conditions in order to put the rotation speed and the Rotation-axis direction or I have to use the option Moving wall fron Boundary Conditions. Maybe both of them?

Thank you..

K.P

 ghost82 December 13, 2012 10:50

you can use moving wall only if you have a surface of revolution (a cylinder is a surface of revolution); you can't use moving wall for the other cases (ex: rushton impeller, which is not a surface of revolution).

Daniele

 krisipanikou December 13, 2012 12:14

Thank you Daniele !

K.P

 ali_mehrabi69 December 14, 2012 08:05

rotation

I am modeling an air turbine in millimeter dimension. and have a problem with these rotation setting!
what should i do?
should i set a rotation velocity in cell zone condition for that region(the zone that is rotating)?or in wall rotation in boundary condition?
or both of them?

Thank u

 ghost82 December 14, 2012 08:18

Set an absolute rotational velocity to cell zone adiacent to your rotating turbine, then set the walls inside this cell zone to rotate with 0 relative velocity.

 ali_mehrabi69 December 15, 2012 03:34

hey

yeah
i think you are true
but, how do i know (for design), how much of the cell zone, should be in rotating zone?maybe just near the turbine?or a bit far or ...?
how much?

tanx

 ghost82 December 15, 2012 10:29

Quote:
 Originally Posted by ali_mehrabi69 (Post 397650) yeah i think you are true but, how do i know (for design), how much of the cell zone, should be in rotating zone?maybe just near the turbine?or a bit far or ...? how much? tanx
Theorically the results don't change in respect to the rotating zone size; your rotating zone must only include your rotating element.

Daniele

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