Corrected speed

Corrected Speed is the speed a component would rotate at if the inlet temperature corresponded to ambient conditions at Sea Level, on a Standard Day (i.e. 288.15K).

Corrected Speed, $N/{\sqrt{\theta}}$, can be calculated as follows:

$N/\sqrt{\theta} = N/\sqrt{T/288.15}$

Corrected Speed is often abbreviated to $Nc$ or $Nr$ (for Referred Speed).

So-called Non-Dimensional Speed $(N/\sqrt{T})$ is proportional to Corrected Speed:

$N/\sqrt{T}= (N/\sqrt{\theta}) / \sqrt{288.15}$

Nomenclature:

• $T$ Stagnation (or Total) Temperature (in Kelvin)
• $N$ Real Shaft Speed
• ${\theta}$ Referred Temperature

In relative form, Corrected Speed, Referred Speed and Non-Dimensional Speed are all measures of peripheral Mach number.

See also

• Compressor map
• Turbine map
• Corrected flow