Modelling Tidal Turbine, general momentum source, body forces
1 Attachment(s)
Hello,
I am trying to model a tidal turbine (HATT) in CFX via a subdomain containing a general momentum source. I am interested in a very specific case, I know the free stream velocity, the TSR and the lift and drag coefficients for iterative 2d sections of my blade. From these I have the equations attached Where Theta rel is the angle of the relative velocity taking into account the rotation. Fazim is around the plane of rotation and the z axis is my rotation axis. I am stuck trying to write the above in a form that will be accepted by the general momentum source options in CFX. If anybody could point me in the right direction your help would be greatly appreciated. |
Are you intending replacing the whole turbine with a single momentum source to model the drag it imposes on the flow?
|
Thank you for replying first off.
Yes, I have my body forces in terms of unit volume. I wished to apply this to a subdomain of my flow. I am now trying manually inputting my expressions from which I got the force equations above and letting ANSYS start from there. When I try and simple put in the above equations as they stand I of course get errors regarding the units. Update: So I have figured it out. I had done all my initial work in Matlab and tried to simply transfer my final x,y,z forces to CFX. ANSYS did not like that, so I built them up from scratch using user expressions and functions. Only thing I am pondering is whether I have to set my subdomain to rotating or whether I have described this aspect sufficiently in my body forces. |
if you are replacing the turbine with a momentum source then no, do not put this in a rotating frame of reference. If the turbine puts a swirl in the flow coming off it then you should include this in the momentum source, but in a stationary frame of reference.
|
Wouldn't a interface do the job?
|
Do what job? This simulation can be done as a single domain so there should not be any need for an interface. However interfaces can sometimes be useful as they are 2D regions which you can apply source terms to.
|
You guys were discussing about doing a domain with a source of momentum... that's why I suggested an interface with this source term!
Bye! |
All times are GMT -4. The time now is 12:05. |