turbomachinery Turbomachinery, in mechanical engineering, describes machines that transfer energy between a rotor (turbine), rotor and a fluid, including both turbines and gas compressor, compressors. While a turbine transfers energy from a fluid to a rotor, a ...

, a velocity triangle or a velocity diagram is a triangle representing the various components of velocities of the

working fluid For fluid power, a working fluid is a gas or liquid that primarily transfers force, motion, or mechanical energy. In hydraulics, water or hydraulic fluid transfers force between hydraulic components such as hydraulic pumps, hydraulic cylinders, ...

in a turbomachine. Velocity triangles may be drawn for both the inlet and outlet sections of any turbomachine. The

vector Vector most often refers to: *Euclidean vector, a quantity with a magnitude and a direction *Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism Vector may also refer to: Mathematic ...

nature of

velocity Velocity is the directional speed of an object in motion as an indication of its rate of change in position as observed from a particular frame of reference and as measured by a particular standard of time (e.g. northbound). Velocity i ...

is utilized in the triangles, and the most basic form of a velocity triangle consists of the tangential velocity, the absolute velocity and the relative velocity of the fluid making up three sides of the triangle.

Velocities involved

A general velocity triangle consists of the following vectors: *''V'' : Absolute velocity of the fluid. *''U'' : Blade Linear velocity. *''V_r'': Relative velocity of the fluid after contact with

rotor Rotor may refer to: Science and technology Engineering *Rotor (electric), the non-stationary part of an alternator or electric motor, operating with a stationary element so called the stator *Helicopter rotor, the rotary wing(s) of a rotorcraft ...

. *''V_w'': Tangential component of ''V'' (absolute velocity), called ''Whirl velocity''. *''V_f'': Flow velocity (axial component in case of axial machines, radial component in case of radial machines). The following angles are encountered during the analysis: *''α'': Absolute angle is an angle made by ''V'' with the plane of the machine (usually the nozzle angle or the guide blade angle) i.e. angle made by absolute velocity V and the direction of blade rotation U *''β'': Relative angle is an angle made by relative velocity and direction of blade rotation.

References

{{Reflist Mechanical engineering Fluid mechanics