Selecting Wind Blade Profile

I found this on a web search Blades

Try googling it yourself.

I wonder if it is possible to scale up the aeromodeller's technique for building a wing using spars and rib sections with a fabric, glass fibre or plastic film covering. Using round rather than rectangular spar sections means that the blade can be twisted the appropriate amount from root to tip before the glue sets. A model aircraft wing is generally stiff enough with one or two main spars plus the leading and trailing edges, but a turbine blade would need several more spars. You would, however be able to use a section which is very efficient at low speeds, and it would be a lot easier to make than by carving timber.

For pumping, the typical wind turbine has a multitude of sheet-metal blades bent into a simple arc. The reason that more care is not taken in making pump-turbine blades is that they are individually very lightly loaded, overall efficiency is low, and the goal is to maximize starting torque to overcome the resistance of the pump at startup. There are commercial makers of these turbines advertising on-line, particularly for places like Australia and the southwestern United States where cattle are often fed from troughs fed by wells pumped by wind-driven pumps. Another configuration option is the sailwing or Cretan style wind turbine, which is even cheaper to make though requiring more maintenance and care. There are plans and construction information available for both kinds, often for free - see for instance CD3WD.

Another way to use wind is to drive a compressor and send the air down the well and use it as an airlift pump. Some companies do that.

Although airlift might have low efficiency, there are advantages due to system reliability.

Perhaps it could be designed with higher efficiency blades and the air compressor mounted up there in the turbine itself?

Maybe an automatic gearbox could be incorporated? Or let it idle as it builds up speed and then have the air compressor cut in at some optimum? Or maybe the air compression stroke can be wind speed related?

Maybe that seems a bit complex? But following that, all you need are air pipes going to the well (which is pretty simple).

This works. I knew a guy in California who did it that way. His wind turbine was a crude two-blade affair turning a permanent-magnet motor salvaged from a mainframe computer tape drive. That drove a DC motor-compressor unit originally built for inflating car tires, and that fed the airlift pump. The system was silent and the water tasted good because it had been aerated. This would be good for some shallow wells here in the Philippines where the water stinks of hydrogen sulfide; aerating it would convert the hydrogen sulfide to sulfur dioxide, which is harmless and doesn't stink.

Interesting with the permanent magnet motor. So it generates electricity to drive the dc compressor? (I am pretty sure that is what you mean). Mounting the compressor right up there on the windmill cuts out the convert to electricity stage and convert electricity to compression stage. That shortening of the chain could save up to 20% of the energy.

Actually I was recently told that sulfur dioxide is pretty dangerous. (almost as bad as H2S) but with a pungent smell. I use it to steralise beer making equipment and it is nasty.

I just checked.

It is not harmless! Certainly a lot more toxic than we realized.

I guess lots of ventilation is in order.

"Interesting with the permanent magnet motor. So it generates electricity to drive the dc compressor? (I am pretty sure that is what you mean). Mounting the compressor right up there on the windmill cuts out the convert to electricity stage and convert electricity to compression stage. That shortening of the chain could save up to 20% of the energy."

That's right - in Fred Zilliox's system the PM motor was used as a PM generator. The use of a generator instead of direct drive to the pump can actually result in higher overall efficiency, because of the inherent inefficiency of wind turbines optimized for pumping - that is, for low speed torque. It also makes the system more flexible, because the excess power can be used to drive other loads. I don't know what Fred used for a "dump" load - he may not have needed one because he deliberately designed his turbine to lose efficiency if it started to "run away;" that is, it was aerodynamically self-limiting. I would have recarved the blades for better efficiency and used a dump load - probably an electric immersion type water heater - to take advantage of any excess power.