Variable pitch implementation

[jeedee23]

Hi Edgar,

Thanks to upload the version with variable pitch angles. I already have a nice view of the matter, with angles, but the solutions I found are not consistent. Pagina's van IJISSET-040407 (2).pdf I use the du06w200 with a chord of 0.25 m, 3 blades, height 1.700m, and diameter 3.400m I Made the linkage file and the corresponding splines to create a cam follower, for TSR 0, 0.5,1.0,1.5 and 2.0. 0.5 is in the zip file.

If you download linkage here you will see the angles I use, but then again, they are not consistent 2022-12-28(at 20h44m09s)_du06w200-tsr05.zip

[jeedee23]

Please see my adaptations in my repository, calculating individual cp per angle gives only one result, which is not average.

[EdgarAMO]

Hi. The actuator model is not suitable for chord-to-radius ratios higher than 10. Your turbine has a radius of 1.7m, therefore your c/R>=0.1. Also the DU06W200 coefficients were obtained from a software called QBlade, it allows you to get lift and drag data at different angles and Reynolds numbers. Since that software uses the vortex panel method, coefficients can only be computed up to angles of 10-12 degrees; however it uses an extrapolation method for higher angles. Hence you have different data for the DU06W200, I suppose it's experimental.

[jeedee23]

HI Edgar,

The chord fo the airfoil is 0.25 m (so c/R=0.7 appr) I Obtained the DU06W200 polars from (http://airfoiltools.com/airfoil/details?airfoil=du06-w-200-dt) I got all of the data (for every angle of attack between -180° to +180) out of qblade, and then I performed a mechanical simulation in linkage(in the attach just download linkage https://www.rectorsquid.com/beta/linkage.msi) That mechanism works but tends to be giving a lot of unwanted stresses (simplifying is needed) And you are right, I will not take into consideration the vortices influences on the 'rear' blades, since that is almost impossible.
It is not experimental, it is on the eve of production.

This evening I'll send you the database in which I developed it. What I need to know is, if the data obtained is correct. I'm a mechanical/electronical/electrical engineer machine builder.

I developed a cam system with 4 stages (ts 0.5, 1.0, 1.5, 2.0) the double cam closes in as tsr rises, at higher TSR the profile is much smoother, so easier. In attach you see already a very overexaggerated variable pitching, to explain. This show you clearly how more efficiency can be obtained using the cam-roller system. Furthermore: for the first model I will add actuators which will act as 'aoa-adapters', and with this feedback, we will see if we need to change the cam. However, it must be doable, durable, and always working well. I developed a cam system with 4 stages (ts 0.5, 1.0, 1.5, 2.0) the double cam closes in as tsr rises, at higher TSR the profile is much smoother, so easier. Once I have the angles,I can make any cam with just the push of a button, and it is generated in Fusion 360 Do you have MS access? I made this in that database since I use it for almost 30 years...

The video (https://youtu.be/aZ0aZlhUXdQ) and linkage file (in the zip) are the same, the airfoils are slightly drawn bigger, just for viewing purposes. The ratio of speed is15 times slower (tsr0.5 at windspeed 10 m/s)

Thanks for your help, mechanical I can manage, it's the calculations, I don't want to be 1000% off...

regards Johan 2023-01-02(at 21h31m25s)_.pdf

2023-01-02(at 21h31m25s)_.zip

[EdgarAMO]

Johan. My email is eamo87@protonmail.com

What data are you talking precisely? The coefficients from QBlade? Also, I try to access that database but the server is down. I don't understand correctly what you want to do with the actuator cylinder code and your linkage simulation. Do you have a function controlling the motion of the pitch?

I also watched your video, it looks great. A friend of mine made her master thesis on something similar to your idea. Here's the link, although her thesis is in spanish but you can translate some bits using google translate: http://132.248.9.195/ptd2019/enero/0784220/0784220.pdf