Specific Speed of turbine

The specific speed of a turbine is defined as the speed of an imaginary turbine, identical with the given turbine, which develops unit power under unit head. Mathematically, specific speed,

P = Power, and H = Net head on turbine.

The specific speed plays an important role in the selection of a type of turbine. By knowing the specific speed of a turbine, the performance of the turbine can also be predicted.

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  1. this is wrong defiition please do not refer this definition.the correct mean of specific speed is that every impulse or reaction turbine gives different efficiency based on there speed range.so there is specific speed range in which a turbine gives maximum efficiency.this range is known as specific speed range.If we have to design a power plant in which we have certain objective like power,Pressure head and speed range of turbine than we can simple calculate specific speed and the can select the turbine according to specific speed range by which we can get maximum efficiency range.