This link models a 3-port valve. It has 3 ports - two inputs and an exit. The link models the two flow paths of the inputs to the exit like a "V" shape, where the tops of the V are the input ports and the vertex is the exit port. Inputs A (Port 0) and B (Port 1) each flow to the exit (Port 2), but not directly between each other. The node attached to the exit port is where the A & B flow paths mix. Flow can go in either direction in each path independently of the other, based on the relative pressures at all three ports. Flow is defined positive going from an input port to the exit, and negative going from the exit port to an input port.

This class embeds two normal GunnsFluidValves to represent the two flow paths. A single overall 3-way valve position governs the relative positions of both GunnsFluidValves. The 3-way position can be defined relative to either path A or B (default A), and the other path's position is calculated such that (path A position) + (path B position) = 1. Intermediate positions partially open both paths, allowing both paths to flow and mix to or split from the exit.

The picture illustrates how the 3-way valve is hooked up in a network, and its equivalence to the two embedded GunnsFluidValves:

Port Connection Rules (These are limitations on the port connection to nodes that the link enforces in run-time):

• No two ports may connect to the same non-Ground node.

Other Rules (These are extra rules you should always try to follow):

• Same as GunnsFluidConductor.

Configuration Data Parameters:

• positionPathB (default = false): This flag configures whether the 3-way position value (0-1) is relative to the path A valve or the path B valve. The default value of false configures relative to path A, so the 3-way position goes to path A (0 = closed) and 1 minus the 3-way position goes to path B (1 = open). Setting this flag true flips it the other way, so the 3-way position would go to path B, and 1 minus the 3-way position would go to path A.
• maxConductivityA: Same as GunnsFluidConductor. This is the maxConductivity term for the path A GunnsFluidValve.
• maxConductivityB: Same as GunnsFluidConductor. This is the maxConductivity term for the path B GunnsFluidValve.
• expansionScaleFactorA: Same as GunnsFluidConductor. This is the expansionScaleFactor term for the path A GunnsFluidValve.
• expansionScaleFactorB: Same as GunnsFluidConductor. This is the expansionScaleFactor term for the path B GunnsFluidValve.
• thermalLengthA: Same as GunnsFluidValve. This is the thermalLength term for the path A GunnsFluidValve.
• thermalLengthB: Same as GunnsFluidValve. This is the thermalLength term for the path B GunnsFluidValve.
• thermalDiameterA: Same as GunnsFluidValve. This is the thermalDiameter term for the path A GunnsFluidValve.
• thermalDiameterB: Same as GunnsFluidValve. This is the thermalDiameter term for the path B GunnsFluidValve.
• surfaceRoughnessA: Same as GunnsFluidValve. This is the surfaceRoughness term for the path A GunnsFluidValve.
• surfaceRoughnessB: Same as GunnsFluidValve. This is the surfaceRoughness term for the path B GunnsFluidValve.
• nonMixingBand (default = 0, must be >=0 and < 1): A non-zero value here enables an optional non-mixing behavior. It defines a band of position values, centered on 0.5, within which both flow paths A & B are blocked. This allows modeling "non-mixing" 3-way valves. The default behavior, when this value is zero, models mixing 3-way valves.

Input Data Parameters:

• position: Same as GunnsFluidValve.
• wallTemperatureA: Same as GunnsFluidValve. This is the wallTemperature term for the path A GunnsFluidValve.
• wallTemperatureB: Same as GunnsFluidValve. This is the wallTemperature term for the path B GunnsFluidValve.

• N/A

• N/A