Feedback on Sencenbaugh's O2 Delight: Windmill Blade Design

A reader in Romayor, Texas questions the efficiency of the windmill blade design Jim Sencenbaugh used in his O2 Delight windmill. Jim Sencenbaugh explains his decision and comments on current and future refinements he's planning.



pix2258a
Top illustration shows how the lift vector of an airfoil positioned with its curved face to the wind impedes windmill rotation. Bottom illustration shows how the lift vector of an airfoil positioned with it's flat face to the wind aids rotation.
ILLUSTRATION: MOTHER EARTH NEWS STAFF
pix2258b
Illustrations showing shape of pressure envelope around an airfoil and its relationship to effective pitch angle.
MOTHER EARTH NEWS STAFF

















Subscribe Today - Pay Now & Save 66% Off the Cover Price

Lighten the Strain on the Earth and Your Budget

Mother Earth NewsAt MOTHER EARTH NEWS, we are dedicated to conserving our planet's natural resources while helping you conserve your financial resources. That's why we want you to save money and trees by subscribing through our earth-friendly automatic renewal savings plan. By paying with a credit card, you save an additional $5 and get 6 issues of MOTHER EARTH NEWS for only $12.00 (USA only).

You may also use the Bill Me option and pay $17.00 for 6 issues.

(* indicates a required item)
Canadian subs: 1 year, (includes postage & GST). Foreign subs: 1 year, . U.S. funds.
Canadian Subscribers - Click Here
Non US and Canadian Subscribers - Click Here