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Vawt , additional DOF for rotor blades

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Hi all .

Is it possible to control the overall blade geometry to keep the blade cord on a constant heading in relation to the wind direction?

I’m not sure if this is built in or if I need to bodge something like making the whole blade an active component, or is there a joint I can control with a turbine controller?

Hi,

when setting up a structural model of a VAWT “pitch actuator nodes” are added automatically. It is then possible to pitch the blades dynamically in two ways:

  1. Use a simulation input file to prescibe how the blade pitch angle changes as a function of time.
  2. Use the controller interface to load a controller library that changes the pitch angle based on the turbine operational parameters.

When you are simulating only an aerodynamic definition of a VAWT (without a structural model) controller cannot be loaded and you can only use option 1.

BR,

David

Thanks very much for the concise reply. I’ll try those methods

Quote from David on 24. September 2022, 13:43

Hi,

when setting up a structural model of a VAWT “pitch actuator nodes” are added automatically. It is then possible to pitch the blades dynamically in two ways:

  1. Use a simulation input file to prescibe how the blade pitch angle changes as a function of time.
  2. Use the controller interface to load a controller library that changes the pitch angle based on the turbine operational parameters.

When you are simulating only an aerodynamic definition of a VAWT (without a structural model) controller cannot be loaded and you can only use option 1.

BR,

David

Could you upload such a simulation input file, because the link you refer to, does not appear in qblade (latest), since a VAWT doe not have a uniform pitching mechanism (unless it is only that that can be achieved with qblade), each blade should have it’s own optimum pitching. Also we don’t see those pitch actuator nodes, nor their position, mentioned?

Thx

Johan

Hi Johan,

when setting up a structural model for a VAWT, pitch nodes are automatically added at all interconnections between blades and struts. When a pitch signal is then transmitted (through a controller or a simulation input file) all pitch nodes that belong to the adressed blade are rotated to pitch the blade around its axis. This really only makes sense for straight blades, but in principal also works for curved blades. So you could try out this feature with the SANDIA 34m template thats available in the download section.

BR,

David

Dear Dr. David,

I still have no idea how to make such a simulation input file in the Turbine Simulation Module for creating an active blade pitching VAWT simulation. Can you give me a start file that I can than addapt to my turbine?

Next to that, I cannot open the file ‘SANDIA34_Main.str’ as this is not supported by my installed apps. Which app do you use to open and edit this kind of files.

Kind regards,

Brecht Timmerman

Hi Brecht,

you can search the documentation for the topics your interested in. More or less each parameter from the simulation setup is explained there, check this search:

https://docs.qblade.org/search.html?q=%22simulation+input+file%22&check_keywords=yes&area=default

You will also find an example for a simulation input file in the “Turbine Behavior” section.

Regarding the strutcural model file: This file cannot be loaded directly but has to be openend from within a turbine definition, check this part of the documentation:

https://docs.qblade.org/src/user/turbine/structure.html

BR,

David

Dear Dr. David, dear all,

Do you know software that calculates the optimal pitch angle for a variable azimuthal angle of the blades for a vertical axis wind turbine?

Kind regards,

Brecht

Hi Brecht,

Im not aware of such a software and would guess that QBlade is as close as it gets to such a tool. Just try experimenting with different pitch curves (of course taking into account the azimuthal AoA distribution of your design) until you get a good result…

BR,

David

Brecht T has reacted to this post.
Brecht T

Oke, thanks!

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A simulation of the Lillgrund windfram in QBlade, using the Dynamic Wake Meandering Model