functionequalPercentage
Valve opening characteristics for equal percentage valve
Information
This function computes the opening characteristics of an equal percentage valve.
The function is used by the model Annex60.Fluid.Actuators.Valves.TwoWayEqualPercentage.
For y < delta/2, the valve characteristics is linear. For y > 3*delta/2
the valve characteristics is equal percentage. In between, a cubic spline is used to ensure
that the valve characteristics is once continuously differentiable with respect to y.
Inputs
| Type | Name | Default | Description |
|---|---|---|---|
| Real | y | Valve opening signal, y=1 is fully open | |
| Real | R | Rangeability, R=50...100 typically | |
| Real | l | Valve leakage, l=Kv(y=0)/Kv(y=1) | |
| Real | delta | Range of significant deviation from equal percentage law |
Outputs
| Type | Name | Default | Description |
|---|---|---|---|
| Real | phi | Ratio actual to nominal mass flow rate, phi=Cv(y)/Cv(y=1) |
Revisions
-
April 11, 2016 by Michael Wetter:
Corrected wrong hyperlink in documentation for issue 450. -
March 30, 2011 by Michael Wetter:
AddedzeroDerivativekeyword. -
June 5, 2008 by Michael Wetter:
First implementation.