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Title: Cyclogiro windmill

Abstract

A cyclogiro windmill has a rotor provided with blades shaped in the configuration of symmetrical airfoils and actuators to pivot the blades about axes parallel to the axis of rotation for the rotor. The actuator for each blade constantly changes the rock angle for the blade, that is its angle with respect to a reference on the rotor, and this modulation is such that the blade in making a revolution around the axis of rotation for the rotor undergoes an interval of static operation wherein its angle of attack is for the most part constant and less than the static stall angle, a short interval where the blade flips to position in which its opposite surface is presented toward the free wind, a short interval of dynamic operation wherein the angle of attack exceeds the static stal angle, another interval of static operation at an angle of attack of essentially the same magnitude as before, another interval of blade flip, and another interval of dynamic operation. During the intervals of dynamic operation, the blades experience a significant increase in lift force without a corresponding increase in drag, so that a high lift-to-drag ratio develops. The blades during dynamic operation furthermore » develop strong vortices which are directed outwardly at the sides of the windmill stream tube, and this increases the width of the stream tube, causing a greater mass of air to flow through the rotor. The short intervals of operation under dynamic conditions enable the blades to extract more energy from the free wind than would be possible if the blade operated solely under static conditions, and this in turn renders the windmill more useful in moderate velocity winds as well as high velocity winds.« less

Inventors:
Issue Date:
OSTI Identifier:
5280579
Application Number:
ON: DE82015930
Assignee:
Dept. of Energy ERA-07-050104; EDB-82-123930
DOE Contract Number:  
AC04-76DP03533
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
17 WIND ENERGY; VERTICAL AXIS TURBINES; DESIGN; TILT MECHANISMS; TURBINE BLADES; AIRFOILS; ROTORS; MACHINERY; TURBINES; TURBOMACHINERY; WIND TURBINES; 170602* - Wind Energy Engineering- Turbine Design & Operation

Citation Formats

Brulle, R.V. Cyclogiro windmill. United States: N. p., 1981. Web.
Brulle, R.V. Cyclogiro windmill. United States.
Brulle, R.V. Thu . "Cyclogiro windmill". United States.
@article{osti_5280579,
title = {Cyclogiro windmill},
author = {Brulle, R.V.},
abstractNote = {A cyclogiro windmill has a rotor provided with blades shaped in the configuration of symmetrical airfoils and actuators to pivot the blades about axes parallel to the axis of rotation for the rotor. The actuator for each blade constantly changes the rock angle for the blade, that is its angle with respect to a reference on the rotor, and this modulation is such that the blade in making a revolution around the axis of rotation for the rotor undergoes an interval of static operation wherein its angle of attack is for the most part constant and less than the static stall angle, a short interval where the blade flips to position in which its opposite surface is presented toward the free wind, a short interval of dynamic operation wherein the angle of attack exceeds the static stal angle, another interval of static operation at an angle of attack of essentially the same magnitude as before, another interval of blade flip, and another interval of dynamic operation. During the intervals of dynamic operation, the blades experience a significant increase in lift force without a corresponding increase in drag, so that a high lift-to-drag ratio develops. The blades during dynamic operation further develop strong vortices which are directed outwardly at the sides of the windmill stream tube, and this increases the width of the stream tube, causing a greater mass of air to flow through the rotor. The short intervals of operation under dynamic conditions enable the blades to extract more energy from the free wind than would be possible if the blade operated solely under static conditions, and this in turn renders the windmill more useful in moderate velocity winds as well as high velocity winds.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1981},
month = {9}
}