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Banki turbine
From Wikipedia
The Banki turbine (also known as the Michell, Crossflow or Ossberger turbine) is a hydropower system similar in appearance to an over-shot water wheel. Unlike the water wheel, however, it uses a nozzle and blades instead of buckets. The "middle" of the Banki turbine is left open and the blades that would normally form the walls of the buckets are angled. It is, in effect, a "leaky" water wheel. Banki crossflow water turbine This image is from Laymans Guidbook on how to develop a small hydro site, published by the European Small Hydropower Association. ... Banki crossflow water turbine This image is from Laymans Guidbook on how to develop a small hydro site, published by the European Small Hydropower Association. ... Energy in water can be harnessed and used,Water sucks!!!!!in the form of motive energy or temperature differences. ... An overshot water wheel standing 42 feet high powers the Old Mill at Berry College in Rome, Georgia A water wheel (also waterwheel, Norse mill, Persian wheel or noria) is a hydropower system; a system for extracting power from a flow of water. ... Rocket Nozzle A nozzle is a mechanical device designed to control the characteristics of a fluid flow as it exits from an enclosed chamber into some medium. ...
Water flowing into the top of the turbine not only spins the wheel by its weight, but as it flows past the blades and into the middle of the turbine, its direction is changed. This extracts additional power via Newton's Third Law. A venturi enhances this effect by funneling the water at a high speed onto the blades. A fluid passing through smoothly varying constrictions experience changes in velocity and pressure, as described by Bernoullis principle. ...
The Banki turbine uses concepts from both impulse and reaction turbine design. This allows it to perform well in a wide range of heads. The system is somewhat similar to the Pelton wheel in concept, but requires less engineering in the wheel itself. In classical mechanics, an impulse changes the momentum of an object, and has the same units and dimensions as momentum. ...
A reaction is the following: In physics, a reaction (physics) is defined by Newtons third law: For every action there is an equal and opposite reaction. The idea that any given force has a pair or opposite force. ...
WWII era steam turbine used for ship propulsion. ...
In fluid dynamics, head refers to the constant right hand side in the incompressible steady version of Bernoullis equation. ...
Pelton wheel from Walchensee, Germany hydro power station A pelton wheel is one of the most efficient types of water wheel. ...
The Banki turbine has lower efficiency than other turbine designs but enjoys a niche market for low cost and home made installations. A reasonably efficient turbine runner can be constructed from pipe sections that are slit to form the blades (70% - 80% efficiency at 10 feet of head). The venturi and associated plumbing may be fabricated with sheet metal tools. It is somewhat more complex than in a over-shot wheel, but by no means difficult. A home made Banki turbine that has same power as a large Diesel engine is within the means of most small and amateur workshops. The diesel engine is a type of internal combustion engine; more specifically, it is a compression ignition engine, in which the fuel is ignited by being suddenly exposed to the high temperature and pressure of a compressed gas containing oxygen (usually atmospheric air), rather than a separate source of ignition...
