Specific speed

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Specific speed

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Here the specific speed definition can be selected. This definition is mainly used for the Approximation functions.

The definitions mainly differ in the units used for rotational speed, flow rate and energy transmission.

Following definitions are available:

General specific speed nq* (dimensionless)

Type number ωs (dimensionless)

Speed coefficient σ

European definition nq

US definition Ns

Asian definition nq'


Furthermore it's possible to select an alternatively specific speed definition using the separate units for Revolutions, Flow rate and Head.

On the bottom side some information for the currently selected specific speed definition is displayed. The Factor on dimensionless value is the factor used to convert the General specific speed nq* to the currently selected definition. Furthermore the Typical range of the specific speed definition for centrifugal, mixed-flow and axial machines is displayed in the table.