George Tonchev

Inventions & Technologies of Renewable Energy

A vertical axis wind turbine (VAWT) with 3 innovative Lift/Drag Jet Blades

The general concept of jet self augmented crossflow turbine rotors based on the additional rotational jet forces. In the hollow blade part (by rotating) the centrifugal force is transforming to jet streams ejected trough outlet nozzles at the trailing blade edge that creating rotational jet torque. At low flow speed, when rpm is low- respective the centrifugal forces are not significant, the rotational jet torque is creating by flow redirection in the hollow blade trough outlet nozzles. JET augmented Savonius vertical axis turbine have the best performance in the comparison of any drag turbine in both flow wind and water.

In the case of Darrieus and Darrieus-like vertical rotors the jet blade is more efficient than the any airfoil blade rotors in very broad turbulent wind speed spectrum.  Jet blades designs transition from a drag mode to a nearly pure lift mode, equating to a surge in power output of 4-fold. All jet blade turbines increased both blade velocity and efficiency.

One of the problems with Horizontal Axis Wind Turbine (HAWT) is that the generators and gearboxes tend to be in an inaccessible position at the top of the structure's tower. This makes them difficult and costly to maintain. Such designs also require gearing mechanisms to ensure they are always facing into the wind. By contrast, VAWT can harness the wind from any direction, allowing them to run more efficiently without the need for such mechanisms. The biggest HAWTs are capable of producing 7-8 MW of power and stand just short of 200m tall, but if you try to make them any bigger they start to become less efficient. One reason is that the weight of the turbine blades becomes prohibitive. As they turn, this places the blades under enormous stress because gravity compresses them as they rise and stretches them as they fall. The larger you make these structures, the more robust they must be in order to withstand these forces. Add to that the cost and difficulty of building the increasingly large towers needed to keep this top-heavy structure stable and you have a major engineering challenge on your hands.

The JET BLADE VAWT gets round these problems. The centre of gravity is at the bottom, making the structure much more stable. The blade inductive loses of the conventional megawatt class VAWT and HAWT are very high. This loses avoided significantly by new invented partly hollow JET BLADE. The inlet apertures of JET BLADE and outlet nozzles of the blade trailing edge formed jet streams that improved air dynamic efficiency. JET BLADE VAWT design is relatively simple. Because of this the technology lends itself to large engineering projects, which is precisely what is needed with wind power. The 140-metre high V-shaped JET BLADE VAWT would be mounted onshore or offshore and capable of generating up to 10 megawatts of electricity - three times as much power as a conventional HAWT of equivalent size. The jet blade turbine design allows to reduce significantly the cost of electricity generated at the level as low as the utility grid prices at present.

See a picture of crossflow JET TORNADO TURBINE here!

Invented jet blades are applicable to free stream water turbines, as well. A short presentation of hydrokinetic plant with new invented jet blade turbines see  here.

Jet self augmented Darrieus and Savonius rotors allowing the turbine to be scaled independently in horizontally or vertically to fit to existing environment.

Number of JET augmented hybrid vertical axis crossflow wind turbines ( fixed to a common shaft Savonius JET scoops and straight JET blades) are developing. The performance coefficient of self JET augmented turbine is increased up to 2 times in the comparison to the conventional blade turbines.

For official patent publications see here

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Author and inventor: © George Tonchev