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-   -   Direction of Rotation of Radial Turbine (http://www.cfd-online.com/Forums/cfx/65763-direction-rotation-radial-turbine.html)

ghoshi1983 June 25, 2009 08:01

Direction of Rotation of Radial Turbine
 
Hi everyone,

I want to do 2D simulation of Radial Turbine and want to change the direction of the rotation of my radial machine. i tried to do that by putting negative value for angular velocity in Pre processor. But didn't work out for me. Since i
am interested in Anti-clockwise roatation of impeller and It always show clockwise rotation in Post processor.

Any suggestion would be great in this concern.

mvoss June 25, 2009 09:21

did this ages ago..
isnīt there smth- like counterrotating domain?

neewbie

ghorrocks June 25, 2009 18:44

Hi,

Don't you just have to reverse the direction of the rotation vector? If the vector was 1,0,0 then it becomes -1,0,0.

Glenn Horrocks

Mehul157@yahoo.com June 26, 2009 06:18

Hi,

If you really want to see the results of clock and anti clock rotational effect. Then you please do a transient simulations, save .trn files and postprocess them all and make the movie of your results. It will show you the things you want to see

ghoshi1983 June 26, 2009 06:40

Thanks for the replies

But still it didn't work out.

As for counter-rotating option, i don't have counter-rotating wall i have everthing moving as one body.

And as for vector values, Actually i didn't understand what you want to say.

Atif

ghoshi1983 June 26, 2009 06:53

Hi Mehul,

Thanks for the reply but i don't want to see the effects of both i just want to change the direction to anti-clockwise.

ghorrocks June 26, 2009 07:18

Hi,

The counter-rotating option is for rotating frames of reference. You set a wall which is stationary (in the absolute frame of reference) to be a counter-rotating wall in the rotating frame. It has nothing to do with what ghoshi is talking about.

The way to reverse the rotation is to reverse the rotation vector. You set a rotation for the rotating frame of reference. It was either a coordinate axis or a vector (eg 1,0,0). Either way just reverse the rotation vector (ie if a coordinate axis then +x becomes -x or if vector +1,0,0 becomes -1,0,0) and then the thing is rotating the other way.

Glenn Horrocks

ghoshi1983 June 27, 2009 08:03

Hi Glenn,

Thanks for the reply it worked out for me. It just changed the coordinate axis sign.

venkat_aero2007 June 19, 2012 10:16

Contra rotating rotor simulation using mixing plane method
 
Hi everyone,

I am trying to simulate flow around Contra rotating rotor using mixing plane method. I have some doubt in defining boundary condition on rotor blade.

I defined Front rotor and Second rotor as Stationary wall.
Front rotor is rotating in Counter clock wise direction (according to Right hand thumb rule). So i define the fluid in the Front rotor region as Moving reference frame which rotates about X- axis (1 0 0) at -1800 rpm (negative sign for Counter clockwise direction), Relative to Cell zone:- absolute.

The second rotor rotates in opposite to that of Firs rotor about X-axis (1 0 0) at 1800 rpm (Positive sign for clockwise direction). relative to cell zone: Opposite to front rotor Fluid

When I check the Relative velocity vector, The Direction of the relative vector for the front rotor is along Counter Clockwise direction which is wrong ( it should be in clock wise direction because of the fact that the blade rotates in counter clock wise direction) but the relative velocity vector for the second rotor looks perfect.

Please can someone help me to define the proper boundary condition.

thanks in advance for your information,

Venkatesh


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