Wind Turbine Blades

I have them spring loaded to return to their original position when the wind dies down.

and

They start up in very low wind and reach a maximum speed based on the strength of the springs. I am still at a trial and error stage with the tensioning of the springs.

spring load. what I see can be one of the problems is that it wold build a resonance and basically be uncontrolable.

IMO, A mechanical governor type of control......I do not think you would have enough mechanical advantage for this.

p911

Have you looked at complex propellors for aircraft, or now ships?

It has been awhile since I flew so I haven't flown a craft with auto feathering capability, though I imagine there is a system around by now.

If it is working for you, good.

Hi,

around which axis are the blades moving if the "self-feathering" is working.

This axis can be oriented parallel to the length of the blades, turning the blades to give lower torque,

or this axis may be oriented perpendicular to turbine and blade axis, folding the blades back to result in lower air-flow within blade area and thus lower torque.

The first version is speed limited by centrifugal force, the second one can go up with speed if folding back the blades.

Any orientation inbetween may be useful too?

Next choice: do you like the the force that operates your mechanism be derived from the centrifugal force or from drag or lift?

I never worked on a mechanism like this but on many other flexural devices so this is interesting me.

(Previous work was on precision instruments.)

Last question: do you like this mechanism to act in a linear manner or like a trigger and complete shutdown if the set-point is reached?

RHABE

I have heard of a similar system some years ago, but I have completely forgotten the reference.

Why not use a simple anemometer input to a simple Controller with variable set limits (Upper/Lower wind velocity) to trigger the feathering mechanism?

D.Ramakrishna Naidu

Standard modern turbines all pitch the blades in high winds. Since pitching requires acting against the torque on the blade, it requires some form of pitch angle control. Many turbines use hydraulic systems. These systems are usually spring loaded, so that if hydraulic power fails, the blades automatically furl. Other turbines use an electric servomotor for every rotor blade. They have a small battery-reserve in case of an electric-grid breakdown. Small wind turbines (under 50 kW) with variable-pitching generally use systems operated by centrifugal force, either by flyweights or geometric design, and employ no electric or hydraulic controls.