New Wave Energy Turbine This new turbine consists of a number of U-shaped sheets attached between a pair of discs, and a cylinder in the middle through which the turbine shaft passes. The turbine will rotate in the same direction, regardless of air-flow direction, but with low efficiency. Here is a picture taken of a model of the turbine: In order to increase the efficiency, a set of valves is needed - one above the turbine and one below it. When a valve is shut, the air-flow will still be able to pass through a duct which leads to the turbine blades. When the upper valve is closed, the lower valve is open, and vice versa. Here is a picture showing the upper valve: The axis of the valve is not centered right on the valve and this enables the air pressure to close it. Each valve is connected to bars which by their own weight ensures that a progressive counter-force is applied to the valve when it shuts, giving a smooth action. For proper action, the valve also needs to be balanced by a weight attached to a bar which is fixed to the valve axle. There is no wear on the valve itself since it doesn't come in direct contact with the walls that surround it. Even if a small amount of air slips through the valve, this air-flow will not work against the turbine to any greater extent. Here are the different working modes of the turbine: The model as seen on the pictures delivers a great response to the vacuum cleaner which drives it. It accelerates immediately when input power increases and it seems to work under a broad range of power inputs. The air-flow which passes with great velocity along the convex side of each blade, just as the blade reaches the duct, creates a decrease in air pressure. Then, as the angle of the blade increases, vortices are most likely to appear on the convex side. The forces thus created, together with forces from air hitting the blades from favourable angles, suggests good efficiency. It's important for the efficiency that air enters from a small opening and is allowed to expand along its way out. The model also reaches high rotational speeds. In order to obtain high rotational speed in a full size turbine, it may be desirable to keep the turbine diameter as small as possible. If the air-flow becomes insufficient, two or more turbines can be connected in parallel, sharing the same shaft but with only one generator. This is the turbine as it is driven by the vacuum cleaner: The turbine emits sound due to the noise created when the edge of each turbine blade is hit by the air-flow. Output sound level can however be significantly reduced by giving the turbine blades the following shape, a shape which will also increase the efficiency: Please note that the blade should probably be shorter than depicted and that the curved white segment on the tip should not be as protrusive. A small sheet, which extends towards the tip, is here used to create an incline. The best method to manufacture the rounded tip has yet to be decided. The fact that the air-flow enters the turbine from another direction, compared to other wave energy turbines, means that there are no severe forces acting along its axis. The simplicity of the turbine suggests low manufacturing costs. Turbine blades could be riveted in place, allowing secure fastening while avoiding too much rigidity. The turbine could also be mounted in a horizontal position as in this shore-based OWC type converter: An even better arrangement of the valves can be achieved by simply keeping them connected via a single bar. Thus the number of moving parts associated with the valves can be reduced from six to three. This also has the advantage of keeping an open valve more or less horizontal, which minimizes its resistance to the outgoing air-flow. Please note that the angle between connected bars in resting position has to be greater than 90 degrees. Also, by letting the horizontal valve edges follow a path which is slightly curved, the closing valve will close faster and stay air tight even if it's not in an entirely vertical position: One can of course experiment with different wall curvatures. This could, for example, be used to relieve some excessive air pressure at the closed valve by letting air pass by when the valve reaches a certain point. This could prevent the generator from overloading or avoid stress caused by too much air pressure. One can also try different weights to be added to the joints keeping the bars together, in order to obtain the desired performance. No additional counter-balance, as mentioned before, should be needed on the valve axles, and this even further simplifies the construction. Although this version may work well when the turbine is in a fixed position, a similar device will probably not be effective in a floating wave power plant. Since the turbine relies on gravity to control the valves it shouldn't be tilted in any direction, as it would be on a wave power plant which is constantly moving about. The following valve arrangement is a solution to this problem: Circles represent springs which will tend to pull each couple of smaller bars together. Because the valve axles are not centered on the valves, the valves need to have some counter-balance. The whole arrangement then becomes completely symmetrical and no matter how you twist and turn the turbine, its valves will be controlled by springs and not by gravity. All bars should be light-weight to ensure a fast action. The spring-controlled construction described here can also be useful if the turbine is meant to be kept still and you want to mount it in a non-horizontal position. When designing any of the valves being described, care must be taken so that there are no wobbling tendencies. Finally, here is a picture showing the turbine blades from up close: The turbine as presented here has not been patented by the publisher of this webpage, so unless there are other patents in effect that stand in the way, the invention should be free to use. Caution: Due to the high rotational speed, any parts of the turbine that break loose could turn into potentially harmful flying debris. The turbine blades must be firmly secured so that they can withstand the very strong centrifugal forces imposed upon them. Additional safety measures are likely to be required in order to protect yourself and others from injury. Keep a safe distance from any moving parts. Protect your eyes with safety goggles. Use the turbine at your own risk and at your own liability. This webpage is currently located at http://home.swipnet.se/nydana/turbine.html Dan Lindgren: Contact Information You are visitor No. 14004 since September 10, 2001.