https://www.youtube.com/watch?v=vdMGdF9g490
VAWT Concept - Vertical-axis wind turbine that uses both drag and lift forces to generate power. A kinematic constraint imposed on the blades determines their angles so that each blade is always generating positively-contributing torque. Blade angles can compensate for a change in wind direction in real time by adjusting the direction of the green 'wind vane' through active or passive control.
https://www.youtube.com/watch?v=vdMGdF9g490
https://www.youtube.com/watch?v=qdUp6i8TNgM
Wind turbine of flipping airfoils 3
Violet gear is immobile in relation with blue frame.
The timing belt drives to connect the violet gear and yellow gears are of transmission ratio i = 2. Such arrangement makes the airfoils rotate haft revolution when the blue frame makes one revolution.
So the wind flow (represented by red arrows) always applies torque on blue shaft of the turbine.
Violet tail rudder helps to rotate the violet hollow shaft of the violet gear (pivoted on brown post) toward the wind flow.
This video was made in reference to https://www.youtube.com/watch?v=vdMGdF9g490
https://www.youtube.com/watch?v=qdUp6i8TNgM
Vertical flipping
Using the airfoils at small angles up to 15° is much more efficient than at 90°, because the pressure difference between both sides of the airfoil is much larger for attached flows than detached flows. This is called a voith-schneider-rotor
https://www.youtube.com/watch?v=zDW7jGOZGo0
Segmented horizontal flipping
I spot a bit of an design flaw here. The flipping of the blades builds up rotative kinetic energy which then is regularly fully dissipated in massive rotative jerks (spontaneous full stops of rotarion) leading to vibrations, loud noise, wear, and drag through those power losses.
https://www.youtube.com/watch?v=xdIw3YOrc-E
Wind turbine of semicircle-shaped airfoils
This looks cool, however it would not work, because the second half of the rotation with the plate on the rear side has a downward sloping airfoil. The Moment from the downward "lift" is larger than the moment from the backward drag. On the first half of the rotation both of these effects act in the same direction, so using 4 coupled airfoils could work (with low efficiency)
https://www.youtube.com/watch?v=yDEjM7EA76U
Violet gear is immobile in relation with blue frame.
The timing belt drives to connect the violet gear and yellow gears are of transmission ratio i = 2. Such arrangement makes the airfoils rotate haft revolution when the blue frame makes one revolution.
So the wind flow (represented by red arrows) always applies torque on blue shaft of the turbine.
Violet tail rudder helps to rotate the violet hollow shaft of the violet gear (pivoted on brown post) toward the wind flow.
This video was made in reference to https://www.youtube.com/watch?v=vdMGdF9g490
https://www.youtube.com/watch?v=qdUp6i8TNgM
Vertical flipping
Using the airfoils at small angles up to 15° is much more efficient than at 90°, because the pressure difference between both sides of the airfoil is much larger for attached flows than detached flows. This is called a voith-schneider-rotor
https://www.youtube.com/watch?v=zDW7jGOZGo0
Segmented horizontal flipping
I spot a bit of an design flaw here. The flipping of the blades builds up rotative kinetic energy which then is regularly fully dissipated in massive rotative jerks (spontaneous full stops of rotarion) leading to vibrations, loud noise, wear, and drag through those power losses.
https://www.youtube.com/watch?v=xdIw3YOrc-E
Wind turbine of semicircle-shaped airfoils
This looks cool, however it would not work, because the second half of the rotation with the plate on the rear side has a downward sloping airfoil. The Moment from the downward "lift" is larger than the moment from the backward drag. On the first half of the rotation both of these effects act in the same direction, so using 4 coupled airfoils could work (with low efficiency)
https://www.youtube.com/watch?v=yDEjM7EA76U
