Darrieus hybrid Savonius wind turbine experiment, DIY a wind turbine at home

This experiment demonstrates the rotation characteristics of a Darrieus wind turbine hybrid the Savonius rotor,showing how drag blades start up the Lift blades.
For more information,refer to：smartservo.org/...
Music by Audionautix.com audionautix.com/

[@GordieGii]

Perhaps if the two halves of the Savonius were on slides and coupled to a centrifugal mechanism so once the rotor has started they shift towards each other to form a cylinder they would present less drag at max speed.

[@SmartServo_org]

good idea

[@themeek351]

Or, perhaps just having a cylinder in the center that will start the rotation!

[@GordieGii]

How would having a cylinder in the center start the rotation?

[@themeek351]

@@GordieGii It's called the Coanda and Magnus effect! These are driven by a motor, so on second thought it probably won't work!

[@GordieGii]

@@themeek351 Yes, it's the motor spinning it that makes it act like an airfoil, and it would need to be off center. If you had a motor attached to the axle you wouldn't need the Savonius to start it.

[@dariusjuodokas9458]

I think the question now is: Does Savonius a) have a physical limit of what RPM can it handle, and since it's attached to the same axis, interferes with the Darrieus' momentum b) get in Darrieus' way physically, i.e. by creating turbulence and/or "hiding" the furthest blade from the stream of the wind The easy way to test this would be to move Savonius out from the middle part of the construction and attach them to the top and bottom of the whole assembly.

[@SmartServo_org]

I have done a test with only the drag blade, and the rotation speed can only reach 50 RPM, which means that the Savonius is dragged by Darrieus when the speed exceeds this speed.

[@SmalltimR]

Hands on proof of concepts - love it - great job!

[@SmartServo_org]

Thank you for your appreciation

[@davidwilker4795]

What if you put the drag blades over the lift blades. Allow the lift blades to free-wheel on the axel, but connect to the lift blades with a sprag or one way clutch. The drag blades can start the lift blades turning, and then "disconnect" from them at higher speeds, allowing the lift blades to spin faster.

[@SmartServo_org]

It should help with efficiency, at least the drag blades don't interfere with the lift blades. But the height should increase a lot.

[@markmmm1737]

@@SmartServo_org Not necessarily. As a simple ready made system I would choose a bicycle rear wheel. The rim on the lift blades and the drag attached to the chain gear. When the lift blades are faster than the drag then it is like free wheeling down a hill on the bike.

[@justtinkering6713]

Now you need to furl the drag turbine after starting

[@BARRABASPY]

Excelente trabajo, felicitaciones.... Seria muy interesante hacer las mismas mediciones pero intercalando un acople "freeweel" entre el eje y el molino savonius. De manera que el Savonius pueda arrastrar al Darrieus pero no a la inversa... Muchas gracias por compartir su trabajo....

[@SmartServo_org]

Thank you for your viewing and suggestions, Since Savonius is located inside Darrieus, even if the two are not coupled, Savonius will still affect the internal flow field and reduce the efficiency of Darrieus.

[@alanhat5252]

@@SmartServo_org yes, but how much?

[@DktheWelder]

Very cool , I didn’t know that they couldn’t self start

[@SmartServo_org]

This video(1:52) explains why it doesn't start by itself => kzbin.info/www/bejne/hYu3f354ZpJ8qKM

[@aurigo_tech]

Well from 125 to 120 to 117 rpm, not that much of a difference. Also the energy/power output might still be higher even with lower rpm, because the turbine could provide more torque?

[@SmartServo_org]

Lower RPM but higher power under the same load is only possible with different wind turbines. But the Darrieus turbine in this experiment is all the same and unloaded. And Savonius is just a burden after the turbine has been started.

[@jommeissner]

You could improve the savonius rotor part: the inner edge of the half barrel must be put a little bit to the other side of the axis, so air can move through the rotor

[@SmartServo_org]

Thank you for your suggestion, I actually made it partially overlap but not much, because efficiency and starting torque are in conflict with each other, and the main purpose of Savonius in this application is for starting. Therefore, the Savonius rotors are stretched more outwards to obtain greater torque.

[@Hanys111]

👍👏 profesjonalne badania. Tak trzeba robić, a nie oszukiwać w wątkach free energy generator

[@SmartServo_org]

This video is not free energy, it just uses Magnus effect to drive wind turbine

[@Hanys111]

@@SmartServo_org oczywiście. Wiem o tym. Czy macie jakieś wyniki: średnica rotora Fi, wysokość L, prędkość rozruchowa wiatru v (m/s), moc P?

[@SmartServo_org]

@@Hanys111 Lift blade : Chord 12 cm,Height 40 cm, diameter is 104 cm. Savonius (1 rotor/1 layer): width 16 cm,Height 18 cm,diameter about 30 cm. The wind speed is as shown by the anemometer in the video (about 2 m/sec), no power is measured.

[@RollinShultz]

OK, it appears from your results that the double savonius losing only 7 extra rpm is a decent trade off for a site with intermittent wind where many starts will be needed. However have you considered adding a clutch to the savonius to allow it to freewheel when after the start process completes?

[@SmartServo_org]

Even with the clutch , the interference still exists when the Savonius is inside the turbine. You can also move the Savonius to the top or bottom, but it will increase the complexity of the structure.

[@justtinkering6713]

Dump the Savonious and allow the blades to pitch.

[@markjmaxwell9819]

These hybrid designs seem to rectify the low wind initial start up issues of some VAWT designs. The name of the game is to get the savonius as small as possible while doing the job it was put on for... Four blade turbines have been tested with good results. With more tweaking and testing a viable large scale power generating design can be attained using this type of hybrid design. With the generator at the very bottom of the tower or column for easier maintenance and using materials that can be recycled a winner.👍

[@SmartServo_org]

This design has existed for a long time. Although it can solve the problem of startup, it has not been popularized, indicating that there are still some problems.

[@markjmaxwell9819]

@@SmartServo_org Having the extra blades makes the initial startup a bit easier. Some one megawatt versions are in service at the moment.

[@SmartServo_org]

@@markjmaxwell9819 I'm glad to hear this, can you provide the link?

[@theexit300]

Or just get a bearing or simple part, disconnecting the cylinder on Vcyl < Vout Also moving the cylinder outside of the inner and get it under. This allows for a much bigger Cylinder and area to start or harvest energy from, due to better efficiency.

[@SmartServo_org]

It's a tradeoff between complexity and efficiency.

[@paulburgess8033]

At some point the drag blades should slide together to form a cylinder

[@SmartServo_org]

It makes sense, but it depends on the tip speed ratio to decide whether to slide. Therefore, it is necessary to know the wind speed and rotation speed at that time.

[@PP.EKOTECH]

SUPER ! GOOD JOB !!! :)

[@SmartServo_org]

thanks

[@mohammedalqraini6376]

Whats components did you use to allow it to rotate? Shaft and hub? This would help please because Im building one for my final year project

[@SmartServo_org]

start up with drag blades

[@adebolaoyedele1206]

Is it possible to get the stl file for the part connecting the savonius to the shaft

[@zaidkiwan5168]

How about making the cylinders close on each others when the turbine picks up speed?

[@SmartServo_org]

Should help with efficiency, but needs to add some mechanism and act at the right time.

[@theexit300]

I was thinking exactly the same, also wouldn't a simple device using the level physic and a sized"-for" mass to get it to close in time, linked by a spring (for re-opening) be a good way to achieve this ?

[@charlespatalud3688]

Hello, can we ask for what materials you used especially in the electronic parts below and the motor

[@SmartServo_org]

refer to => kzbin.info/www/bejne/b3LHoZqdlrSZfJI assemble => kzbin.info/www/bejne/eJ2sfmdpm7ejbJI But this video only uses it to measure RPM, no need to control the motor.

[@narayannp9742]

@@SmartServo_org 0⁰⁰0⁰

[@MohamedSaafan-k9v]

what's the material used for the drag blades?

[@SmartServo_org]

Thick cardboard, just for experimentation

[@ramadhan2635]

what material for the type of turbine in it

[@SmartServo_org]

The inner Savonius rotor is made of cardboard, and the outer blades are 3D printed(PLA).

[@ThrashLawPatentsAndTMs]

@1:30 "which is faster than before" ... -- "faster than before WHAT...?"

[@SmartServo_org]

compared to the earlier experiments => kzbin.info/www/bejne/on24qmaZl6d4i5o @3:20

[@ThrashLawPatentsAndTMs]

@@SmartServo_org ah; Thank you. "before" but "after and elsewhere" ... :-) Off to watch it now...

[@wind-9243]

эта турбина нерабочая! под нагрузкой сразу встанет 😀

[@SmartServo_org]

This video will give you a hint => kzbin.info/www/bejne/b5zHg32Iod5-iMksi=h3eBx0Khl2wMS5Pj

[@wind-9243]

@@SmartServo_org 😀😀😀Это разве нагрузка?... Для того чтобы выработка была приемлемой нужно, чтобы ветряк был огромным. Эта модель ущербна и не стоит вложений..