Turbomachinery

Turbomachinery includes all types of machines through which a fluid or a solids-laden fluid flows and which are equipped with a vaned impeller for the exchange of mechanical energy and flow energy.

In contrast to positive displacement machines (see Positive displacement pump) flow deflection by the impeller vanes is the characteristic feature of turbomachinery in this energy exchange (see Principle of conservation of momentum). 

Depending on the direction of the energy transfer, i.e. from the turbomachinery’s shaft to the fluid or vice versa, a distinction is made between "driven machinery" (e.g. centrifugal pump, turbo-compressor, ventilator, aircraft propeller or airscrew, ship's propeller) and "prime movers" (e.g. steam, gas, wind, liquid, and in particular, water turbines).