Wind turbine rotation through UDF in FLUENT
 

Hi,

I am modelling a wind turbine blade. I want in FLUENT that I specify inlet velocity at its inlet and the FLUENT let itself rotate the blade due to this wind velocity. However, I will specify the parameters (not rpm obviously) through UDF as I want to use dynamic mesh for this purpose. Please tell me if this approach is OK.

Secondly, I am stuck in UDF because all the UDFs I have had serached up until now have used rpm inside the UDF. This is not required (perhaps) in my case because I want to calculate FLUENT its rpm throuh rotating the turbine. In this case what parameters should I specify, please help me out.

Regards,

You might be better off using an MRF for this. See the FLUENT documentation for details.

The MRF still requires the user to input RPM while we want Fluent itself to determine rpm or give torque while we input only UDF and inlet velocity

I see. Yeah I've never back-calculated RPM before.

Inlet velocity and turbine rotation rate are inputs, torque is an output. To find torque, you need to know the rotation rate. If you want to determine rotation rate given a certain torque (perhaps no torque or just friction at the axle) I don't believe there's a straightforward way. I see two reasonable options:

You could write a UDF controlling an MRF that calculates the torque every N iterations and guesses a new rotation rate that will (hopefully) result in your target torque.

You could write a UDF for a transient dynamic mesh that accelerates the turbine every time step based on the torque as . The Six DOF dynamic mesh solver may be appropriate, but I've never used it, and can't say for sure.

FLUENT--let itself rotate the blade due to this wind velocity
 

Hello Jamshed,

I am also trying to simulate exact the same(FLUENT--let itself rotate the blade due to this wind velocity). but don't have any idea/clue how to proceed. i performed some simulations by using dynamic mesh(rotary motion to mesh) and was able to get results. but for this case, my search is on :confused: .could you please help me with this? did you finish with your case?

P.S-could you share any of the UDF's you found for this simulation! please

Thanks in advance

Regards,
Bharatt

same my problem, I don't have any idea :(:(
P.S-could you share any of the UDF's you found for this simulation! please ;)
thanks so much
email: nguyenkhangninh.hk@gmail.com

wind turbine spanwise distribution of lift and drag
 

hi;
i am modelling a flow over a wind turbine blade using fluent, i want to know how can i plot the span wise distribution of the lift force, i mean that i created 10 iso-surfaces on the blade (span wise direction) and now i want to know the value of lift and drag on each one.
i think that i need a UDF or Scheme programming to do this.
can you help me.

did anyone solve this problem,i am trying to solve my problem which is related to this subject,i will be very happy if you explain this subject

best regard
with respect

any news?
 

Hello guys.
I have the same problem? anyone could do that?

Hi All,

This is not my specialist topic, but I have a few thoughts:

Let's define the term "free rotation" to mean the rotation that will occur when a turbine is put in an airflow and allowed to rotate without any other torques (not even resistance at the bearings).

1) Free rotation in the wind is not a very relevant question for wind turbines, because the whole point is that the turbine drives a generator. The torque required to drive the generator will depend on the gearbox (if there is one -- see answers here https://www.quora.com/Does-a-wind-tu...-the-generator) and the generator. It is presumably possible to design the generator for optimum efficiency at a specific windspeed -- see the graph near the end of Stephan Mussgnug's answer here https://www.quora.com/Why-is-3-the-o...-say-5-or-more. So in simulations, it probably makes more sense to specify a range of speeds in advance, and deduce the available power.

2) If you really want to simulate free rotation, one technique would be to do several simulations at pre-specified rotation speeds, hunting around until you found zero torque. This could well be easier than the alternative...

3) If you really want to simulate the motion of a body under forces and torques from fluid flow, check out the Six DOF model in Fluent. (DOF stands for Degrees of Freedom, but the model is called Six DOF in the Help files, in the section "Using Dynamic Meshes".)

4) For placement of wind turbines, for example multiple wind farms in landscape topography, the blades of the turbines are not included in the model in detail -- instead, each turbine has an "actuator disk" model.

I would very much welcome corrections and real-world experience from other commentators.

Good luck!
Ed