equalPercentage

Equal-percentage valve characteristic with leakage (Buildings.Fluid.Actuators.BaseClasses.equalPercentage): linear below delta0/2, R^(y-1) above 1.5delta0, a cubic Hermite joining them*

FastSmoothBuildings.Utilities.equalPercentage, function (source)

Purpose

Equal-percentage characteristic φ(y) of a valve with leakage, once continuously differentiable.

Equations

With the rangeability R, the leakage l and δ₀ = delta0:

Range	φ
y < δ0/2	l + y (Rδ0−1 − l)/δ0
δ0/2 ≤ y ≤ 1.5 δ0	cubic Hermite polynomial matching the value and slope of both neighbours
y > 1.5 δ0	Ry−1

φ(0) = l, φ(1) = 1; the linear branch passes through R^δ₀−1 at y = δ₀. C1.

Relation to Buildings

Buildings.Fluid.Actuators.BaseClasses.equalPercentage.

Use

The two-way and three-way valves of Hydronics pass it, their opening limited to [0, 1] by smoothLimit, to valveConductance.

Revisions

• October 2026: moved from trano's FastModel.Utilities.