This experiment demonstrates the start-up and rotation characteristics of a Darrieus wind turbine. For more information,refer to:smartservo.org/... Music by Audionautix.com audionautix.com/
A well designed Darious, i understand, has its highest efficency with a tip speed ratio closer to 6 when loaded and is operating at just over 35% efficency.
Very nice !! To catch a little extra wind, you could make horizontal plates or airfoils-plates at the top and bottum and maybe even in the middle to test self start. How would that compare to your build in magnus ?
Thanks for your comment, it is true that many Darrieus wind turbines have winglets at the blade tips, which should improve efficiency and perhaps startability as well. But in designs where the blades are very narrow (low solidity for high efficiency) the starting device is still required , because the winglet cannot change the angle of attack of the blade to avoid stalling. This is why I use the Magnus effect.
Id like to see a video how you made the airfoil. I want to know how you attached the film to the 3d printed material. Is the film monocote? Your test are very informative. Thank u so much..
I think the point of choosing a generator is to match the torque curve to the wind turbine for high efficiency, low cogging torque and friction for easy starting.
I think if you made the wings longer it would self start; maybe 1M. There's a golden ratio to design a self starting lift vawt and it's different with each wing type. It's a balance between swept area diameter, chord, and wing length combined with correct angle of attack which for the NACA wings in the series you are using seems to be around 1-6 degrees depending on where the mount is on the chord
The starting problem of Darrieus turbines is the stall of the blades => ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-OZTNKB1-IrA.html 1:51 ,making the blades longer doesn't change that. common practice is to make the blades wider, which can start but at very low speeds and is inefficient.
@@SmartServo_org I'm reasonably aware of the dynamics of lift type vawts and longer blades do help as well as possibly try a different wing profile ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-1gTqX7xE21c.html
Sometimes people use a small savonious type turbine inside. The inside savonious turbine radius should be small enough that it's tip speed ratio (tsr) is closer to 0.8. If his darious is operating at 3.3 tsr then 0.8/3.3=0.24 sugesting that the savonious should sweep about 1/4 radius of the darious radious. But he really needs to redesign his darious to get a higher tsr closer to 6. In which case the savonious diameter would need to be 0.8/6 = 0.13333 or pretty close to 1/8th (.125) that of a darious with a 6 tsr. The savonious shouldn't be tall either. It's mainly purpose isn't to generate power. Rather it's only there to generate starting torque. It also doesn't need to be on the inside. It could be placed ontop or below.
@@kreynolds1123 Yes, it's the traditional way, but the Savonius blades have much less starting torque than the Magnus rotors => ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-qAYjPSDGPo4.htmlsi=0fGEe-6f5zkJhroy
@killerwolf7676Why do I ask - I spend quite a lot of time trying to find some tests. THERE IS NO ANY. At least no successful tests on vertical generators. People claim, independent tests, efficiency curves on a paper or in PDF, other blablablabla. But no real non-stop video from really independent "amateurs" where an inverter is connected and this vertical things deliver something reasonable - 100-200-1000W. The maximum I have seen was in order of 10 W from a 1.5-2meters big turbine. As an example ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-mxSDieRRcz8.html There is another video similar to this one, where as fast as load is applied, the turbine slows down and generates less then a bicycle dynamo even at a strong wind..
@@TushhsuT The power generation experiment is in progress. In addition, the Darrieus wind turbine is a lift type and must operate at high speeds to achieve its full potential. If the wind speed and rotational speed are not disclosed in the video, there is no way to know the tip speed ratio TSR, making it impossible to determine whether the turbine is started or not. Many lift windmills actually only rely on drag to operate. Low power is not the point but to be able to clarify what the problem is.
I designed one that is similar, but it's self starting. I have a short video on RU-vid. If it's not self starting it's of no use. Good luck I like the structure built into the airfoil.
One of the characteristics of the Darrieus wind turbine is that when the blade area is wider relative to the swept area of the wind turbine (the larger the solidity), the easier it is to start, but the speed that can be achieved is slower, which means lower efficiency.In order to achieve high efficiency, some turbines will design the blades to be very narrow, so it is difficult to start by themselves, but after starting, they can reach a very high speed, usually the speed of the blades can be more than 4 times higher than the wind speed. It is helpful to understand this question by measuring how many times the speed of your blades is faster than the wind speed.
The trouble besides not starting is that even though it can go fast, it has no torque. Once you start loading it the tsr goes way down, as well as the rpm.
Unless the rotational speed is to be known, there is usually no need to install a sensor in the VAWT. First decide whether it is a lift type or a drag type, and then start making after understanding its characteristics. => ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-OZTNKB1-IrA.html
@@jawadmezaal5192 You can use a magnetic encoder to detect the azimuth angle, It is more reliable in harsh environments. To pitch the blades is more complicated. If you can avoid "losing step", you can use stepping motors to control the pitch, or you need a closed-loop servo system, which could be too expensive to use on such a small wind turbine.