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Hydropower (from Ancient Greek ὑδρο-, "water"), also known as water power or water energy, is the use of falling or fast-running water to produce electricity or to power machines. This is achieved by converting the gravitational potential or kinetic energy of a water source to produce power. [1] Hydropower is a method of sustainable energy ...
A consequence of Newton's second law of mechanics is the conservation of the angular momentum (or the “moment of momentum”) which is fundamental to all turbomachines. . Accordingly, the change of the angular momentum is equal to the sum of the external mome
Hydrostatic head is also used as a measure of the waterproofing of a fabric, commonly in clothing and equipment used for outdoor recreation.It is measured as a length (typically millimetres), representing the maximum height of a vertical column of water that could be placed on top of the fabric before water started seeping through the weave.
Hydropower is a flexible source of electricity since stations can be ramped up and down very quickly to adapt to changing energy demands. [31] Hydro turbines have a start-up time of the order of a few minutes. [37] Although battery power is quicker its capacity is tiny compared to hydro. [2]
Heron's fountain is not a perpetual motion machine. [2] If the nozzle of the spout is narrow, it may play for several minutes, but it eventually comes to a stop. The water coming out of the tube may go higher than the level in any container, but the net flow of water is downward.
Turgo turbine and generator At Milford Sound, New Zealand. The Turgo turbine is an impulse water turbine designed for medium head applications. Operational Turgo turbines achieve efficiencies of about 87%.
This allows a new turbine design to be scaled from an existing design of known performance. The specific speed is also the main criteria for matching a specific hydro site with the correct turbine type. The specific speed is the speed with which the turbine turns for a particular discharge Q, with unit head and thereby is able to produce unit ...
In 1883, Francis completed his calculation standards for water flow rates, now known as the Francis equation or Francis formula, usually used in fluid dynamics in conjunction with calculating weirs. The equation is = / where: Q is the discharge in cubic feet per second over the weir,