Editing Centrifugal compressor (section)

=== Collector ===
[[File:Main components of a centrifugal compressor in isometric view.svg|thumb|upright= 1.35|Figure 1.4 - Centrifugal compressor model illustrating the main components]]
The collector of a centrifugal compressor can take many shapes and forms.<ref name="Japikse&Baines"/><ref name="Aungier"/> When the diffuser discharges into a large empty circumferentially (constant area) chamber, the collector may be termed a ''Plenum''. When the diffuser discharges into a device that looks somewhat like a snail shell, bull's horn, or a French horn, the collector is likely to be termed a ''volute'' or ''scroll''.

When the diffuser discharges into an annular bend the collector may be referred to as a ''combustor inlet'' (as used in jet engines or gas turbines) or a ''return-channel'' (as used in an online multi-stage compressor). As the name implies, a collector's purpose is to gather the flow from the diffuser discharge annulus and deliver this flow downstream into whatever component the application requires. The collector or discharge pipe may also contain valves and instrumentation to control the compressor. In some applications, collectors will diffuse flow (converting kinetic energy to static pressure) far less efficiently than a diffuser.<ref name="Heinrich&Schwarze">
{{cite journal
| last1 = Heinrich | first1 = Martin| author-link1 = Martin Heinrich
| last2 = Schwarze | first2 = Rüdiger| author-link2 = Rüdiger Schwarze
| title = Genetic Algorithm Optimization of the Volute Shape of a Centrifugal Compressor
| journal = International Journal of Rotating Machinery| date = January 2016
| volume = 2016| pages = 1–13| doi = 10.1155/2016/4849025| doi-access = free}}</ref>

Bernoulli's fluid dynamic principle plays an important role in understanding diffuser performance. In engineering situations assuming adiabatic flow, this equation can be written in the form:

Equation-1.4
:<math>\left(\left(\frac {v^2}{2}\right)+\left(\frac {\gamma}{\gamma-1}\right)\frac {p}{\rho}\right)_4 = \left(\left(\frac {v^2}{2}\right)+\left(\frac {\gamma}{\gamma-1}\right)\frac {p}{\rho}\right)_5</math>

where:
*{{mvar|4}} is the inlet of the diffuser, station 4
*{{mvar|5}} is the discharge of the diffuser, station 5
*(see inlet above.)