functionequalPercentage

Equal percentage characteristic

Extends from baseFun (Base class for valve characteristics).

Information

This characteristic is such that the relative change of the flow coefficient is proportional to the change in the opening position:

d(rc)/d(pos) = k d(pos).

The constant k is expressed in terms of the rangeability, i.e., the ratio between the maximum and the minimum useful flow coefficient:

rangeability = exp(k) = rc(1.0)/rc(0.0).

The theoretical characteristic has a non-zero opening when pos = 0; the implemented characteristic is modified so that the valve closes linearly when pos < delta.

Inputs

TypeNameDefaultDescription
Realpos (from baseFun)Opening position (0: closed, 1: fully open)
Realrangeability20Rangeability
Realdelta0.01

Outputs

TypeNameDefaultDescription
Realrc (from baseFun)Relative flow coefficient (per unit)