Additional views

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Additional views

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The following information can be displayed in the diffuser dialog using the "Additional views" button:


3D model of the currently designed diffuser geometry as well as spiral surfaces.

Informational values

Velocity ratio cOut / cIn

Deceleration ratio

Length L

Length of the diffuser

Angle to centerline φ

Angle between connecting line impeller-center  outlet branch center and diffuser start section

Center distance C

Distance from the h-line to the center point

Cone angle ϑ

Cone angle from DIn to DOut over the length L

Max. theoretical cone angle ϑmax

ϑmax=16.5°(DIn/2/L)½ , see Gülich,
not for turbines

Radius of centerline R

Radius of middle line (for radial diffuser only)

Diffuser outlet center C

Spatial position of diffuser outlet

Inlet & Outlet information

Equivalent diameter D

Diameter of the equivalent circle at the diffuser inlet / outlet

Area A

Area at diffuser inlet / outlet

Velocity c

Velocity at the diffuser inlet / outlet

Pressure p

Pressure at the diffuser inlet / outlet

Total pressure pt

Total pressure at the diffuser inlet / outlet

For turbines and compressor additional information is visible:

Temperature T

Temperature at the diffuser inlet / outlet

Total temperature Tt

Total temperature at the diffuser inlet / outlet

Density ρ

Density at the diffuser inlet / outlet

Mach Number Ma

Mach Number at the diffuser inlet / outlet


Spiral losses are predicted using the theory of Aungier [Outlet Volute only]:

Cone loss coefficient

Wall loss coefficient

Overall loss coefficient

Cross sections

Diffuser cross sections (z-r)

Area progression

Area distribution (l-A)