Diagram of a Turbine
History of TurbinesThe following information is taken from the web site of:
The American Society of Mechanical Engineers
"Near the start of the nineteenth century, the application of scientific methods of analysis and experimentation, along with the increased availability and reduced cost of iron, led to many improvements in design of water wheels and to the development of hydraulic turbines.
In France, Jean Victor Poncelet introduced the use of curved blades which more than doubled the efficiency of an undershot wheel. Curved blades reduced the hydrodynamic turbulence losses from the water impact on the wheel. In 1826, Poncelet suggested turning his wheel on its side to permit the water to exit smoothly through the center instead of turbulently reversing direction and flowing out the bottom.
Poncelet's wheel and the modifications he proposed, influenced his countryman Benoit Fourneyron, who in 1827 built the first successful water turbine. It was an outward-radial-flow device with guide vanes inside the wheel. Its efficiency was 80% at full gate.
Samuel B. Howd of Geneva, New York also implemented Poncelet's suggestion, but retained his inward flow arrangement to produce the first successful inward-flow turbine, in 1838. Inward flow resulted in smaller, less expensive wheels that ran at higher speeds than outward-flow wheels.
Around 1849, James B. Francis improved Howd's design, and advanced the technology by performing accurate tests, publishing the results, and formulating rules for turbine runner design. He helped the United States become a leader in the development of hydraulic turbines and his name became synonymous with inward-radial-flow turbines.
Several American manufacturers improved on Francis' design, evolving different forms of mixed flow turbines that combined radical and axial flow. The mixed-flow wheels ran at higher speeds and produced more power. They were well suited for the low-head applications common in eastern United States.
Jonval axial-flow turbines, developed in France in 1837, were introduced to the United States around 1850 and enjoyed extensive use. the smaller size, higher speed, higher power, lower costs, and ability to operate efficiently with variable water levels caused these and other types of hydraulic turbines to replace the vertical waterwheel as the primary source of power in American industries."
An example of a turbine is the Little Giant Turbine. It is described as a scroll or central vent turbine. The bottom of the turbine sits on the bottom of a tail race. Water enters the rectangular gate box, turns the runner and then finally exits the turbine through its top and bottom openings. This design of a turbine is considered to be most efficient because there is less restriction by allowing water to exit in two different directions.
More information about turbines may be found on a web site describing the Kinne collection of water turbines. Web Site for The Kinne Collection of Water Turbines
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This page was last updated on 03.02.09