19-12-2012, 06:34 PM
Definition of a Turbomachine
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Definition
A turbomachine is a device in which energy is transferred either to or from a continuously flowing fluid by the dynamic action of one or more moving blade rows
The word turbo is a Latin origin and implies that which spins or whirls around
A rotating blade row, a rotor or an impeller changes the stagnation enthalpy of the fluid moving through it by either +ve or –ve work. The changes in enthalpy are linked with pressure changes.
A pump: work is done on fluid
A turbine: work is done by fluid
The definition precludes consideration of positive displacement machines such as piston pumps and piston steam engines.
Classification of Turbomachines
Major subdivisions
A. Power classifications (power is added or extracted from the fluid)
Pumps are power addition machines and include liquid pumps, fans, blowers and compressors.
Fluids are water, fuels, air, steam, refrigerants.
Turbines are power extraction devices and include windmills, water wheels, hydroelectric turbines, automotive engine turbochargers, gas turbines.
Fluids; gases, liquids, mixtures.