Wind energy machines are proposed in a wide variety of designs. The simplest is a form of windmill, with several blades mounted on a hub like an aircraft propeller spinning on a horizontal axis. These suffer from known problems. They are unresponsive to low wind speeds, and are liable to overspeed and suffer damage at high wind speeds. They are also relatively tall structures and are unsightly.
The blade tips travel at high velocity, even when operating in modest winds. This tip speed may be close to the speed of sound. The noise of such windmill designs is well known and is a major disadvantage. Changing the direction in which the windmill is facing becomes difficult when the blades are rotating, due to the creation of kinetic energy of the rotating blades around their horizontal axis, which resists changes in direction.
Squirrel cage type systems are highly directional and are relatively inefficient. Vertical rotor designs require the wind direction to be diverted by as much as 90 degs, thus wasting considerable energy.
They do have certain features which are advantageous. Thus they are easily directed at the incoming wind. They can be lower then propeller type designs and thus less objectionable. They are less liable to overspeed in high winds and less liable to damage. The turbine blades can be shorter, thus avoiding problems of excessive tip speeds common to windmill systems.
Turbine designs however have been of various types. The typical turbine is a multi-blade disc somewhat like a fan, with the blades being twisted so as to convert wind energy into rotation as the air passes. This type of turbine is not suitable for a vertical turbine design.
Water turbines also suffer from numerous disadvantages, and the principles of the invention can be applied to water flows, as well as to fluid flows such as air flows. Accordingly it is desirable to design a turbine machine, using a vertical axis turbine rotor, and mounted in a housing which can be directed at the incoming wind.