TWO EASY ALTERATIONS COULD RESULT IN 70-100% MORE POWER

[Usman]

I just bought a turbine, looks similar to the AirX 403, but has an output of 48V/1KW at 12.5m/s from a 1.8 meter Carbon Fiber 5- bladed rotor.

I was thinking of doing a couple of changes to it to increase the perofrmce at lower wind speeds and output at any given wind speed, with two simple alternations.

1. -Putting on blades extenders at the root of the blades to increase the swept area. (making it a 2.3m rotor dia.). Extending at the tips is a lot more risky and difficult to do.
   
2. -Fabricating a new hub for three blades instead and replacing the 5-bladed rotor with a 3-bladed one.
   
   

I would appreciate any suggestions to this. My target is to have lower wind speed start ups and higher KW rating, as the generator is capable of 200% overload.

A-My understanding is that reducing the number of blades would result in higher rpm (meaning higher KW output) at any given wind speed, since the originally 5-bladed rotor was designed for lower rpm and less noise, which is not an issue for me.

B-By extending the blades at the roots would result in lower wind start-ups.

Am I thinking on the right track?

Regarding the blade extenders,

Would it be more efficient to add a simple metal pipe (20-40mm dia.) or would I be better of extending at the tips with fiberglass extension, which is much more complex than adding simple metal pipe extenders?

Any idea how much gain I could expect from:

i-Reducing the number of blades from five to three

ii-Extending the blades at the root, from 1.8m dia to 2.3m.

iii-Both of the above combined.

Any ideas or suggestions would be highly appreciated.

Thanks, Usman.

[wdyasq]

A wind turbine should be considered a 'Wind Turbine System'. Any thing modified has an effect over the 'system'. Your modifications may or may not give an improvement.

But - it is your machine and I doubt it is criminal to modify it.

Please inform us of the modifications and their effects as it may save others of the expense if it doesn't work or help them if it does.

Usually, the most positive modification on a wind machine is to increase tower height.

Ron

[Flux]

Sounds like a pup like the air x.

I doubt that you will ever see the rated output for more than a few seconds and they are probably relying on that for alternator survival so I would not try for more than the 1kW.

Being optimised for high speed it is probably useless at 10mph so your proposed mods may work to some extent. Increasing blade diameter to 8ft will help the low wind performance but you will need to increase speed. Reducing the number of blades may work. Possibly keeping the same number and altering the angle may work.

As Ron said, the whole thing is designed as an issue and what effect any changes you make have depends on lots of details that we don't have.Need alternator characteristics and lots of details to form much of an opinion.

I feel sure that you will get some improvement with blade extenders unless the alternator is already too fast. Probably those blades are not good low wind devices, I would be tempted to keep the original number.

If start up is completely satisfactory and you want more speed then try 3 blades.

I doubt if you can make it worse.

Flux