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 TWaung June 25, 2011 14:24

Vertical Axis Wind Turbine Rotating Domain Problems

Hello,

I am trying to run a transient simulation of the rotating blades of a vertical axis wind turbine in CFX. My domain is thin in order to approximate a 2D simulation.

My domain looks similar to this image

http://docsdrive.com/images/ansinet/...11-302-312.jpg

There is a rotating ring shaped domain containing the blade profiles, and a stationary domain on the inside and outside of the rotating domain. The wind flows from left to right.

The problem I am encountering is that it appears that the fluid within the rotating domain is being given an angular velocity. I have run a mesh similar to the one shown but without any blade geometry and I find that the fluid in the rotating domain still has an angular velocity.

I was expecting the flow to pass straight through the rotating domain unless it was disturbed by an object like the turbine blade.

Does anyone have any suggestions on how to set up a simulation like this?

Here are some of the settings I am using.

Analysis Type: Transient
Stationary Domains: Stationary
Rotating Domain:
- Rotating at a fixed angular velocity

For the interfaces between the stationary and rotating domains, I am using:

Interface Type: Fluid Fluid
Interface Models: General Connection
Frame Change/Mixing Model: Transient Rotor Stator
Pitch Change: None
Mesh Connection Method: GGI

Thanks for any suggestions!

 ghorrocks June 26, 2011 06:16

You are viewing the velocity in the local frame of reference. What you are looking for is the velocity vectors in the absolute frame - so look at the variable "Velocity in Stationary Frame".

 TWaung June 26, 2011 10:52

Hi Glenn,

Ahh, now everything looks fine. Thanks very much!

 heatdrive April 29, 2012 11:17

Quote:
 Originally Posted by TWaung (Post 313554) Hello, I am trying to run a transient simulation of the rotating blades of a vertical axis wind turbine in CFX. My domain is thin in order to approximate a 2D simulation. My domain looks similar to this image http://docsdrive.com/images/ansinet/...11-302-312.jpg There is a rotating ring shaped domain containing the blade profiles, and a stationary domain on the inside and outside of the rotating domain. The wind flows from left to right. The problem I am encountering is that it appears that the fluid within the rotating domain is being given an angular velocity. I have run a mesh similar to the one shown but without any blade geometry and I find that the fluid in the rotating domain still has an angular velocity. I was expecting the flow to pass straight through the rotating domain unless it was disturbed by an object like the turbine blade. Does anyone have any suggestions on how to set up a simulation like this? Here are some of the settings I am using. Analysis Type: Transient Stationary Domains: Stationary Rotating Domain: - Rotating at a fixed angular velocity For the interfaces between the stationary and rotating domains, I am using: Interface Type: Fluid Fluid Interface Models: General Connection Frame Change/Mixing Model: Transient Rotor Stator Pitch Change: None Mesh Connection Method: GGI Thanks for any suggestions!
would you please tell me,what software did you use to meshing the model? i'm doing the same project as you are, but the problem is, the solver state that my interface between stationary and rotating domain require pitch angle, but i don't know what's the value for my pitch angle...i really hope that you can help me, really appreciate your advice..

 heatdrive May 1, 2012 03:14

Quote:
 Originally Posted by ghorrocks (Post 313614) You are viewing the velocity in the local frame of reference. What you are looking for is the velocity vectors in the absolute frame - so look at the variable "Velocity in Stationary Frame".
i'm doing the same project as him, but the problem is, the solver state that my interface between stationary and rotating domain require pitch angle, but i don't know what's the value for my pitch angle...i really hope that you can help me, really appreciate your advice..

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