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Two-phase fluid and thermal liquid network interface

**Library:**Simscape / Fluids / Fluid Network Interfaces

The Interface (2P-TL) block represents a flow connection between a two-phase fluid network and a thermal liquid network. Pressure, temperature, and mass flow rate are equal at the interface. The fluid properties of each network are not transmitted across the interface. To conserve fluid properties, ensure that the fluid properties blocks on either side of the interface block have the same network properties.

The fluid on the two-phase fluid side must be subcooled. If the fluid vapor fraction at the two-phase fluid port becomes nonzero during a simulation, the block returns an error.

Mass is conversed through the block:

$${\dot{m}}_{TL}+{\dot{m}}_{2P}=0,$$

where:

$${\dot{m}}_{TL}$$ is the mass flow rate at port

**TL**.$${\dot{m}}_{2P}$$ is the mass flow rate at port

**2P**.

The internal and port pressures are equal:

$${P}_{TL}={P}_{I}={P}_{2P}.$$

The temperature is maintained between the two fluid ports. The energy balance over the interface is calculated as:

$${\Phi}_{TL}+{\Phi}_{2P}={\dot{m}}_{TL}\left({u}_{I,TL}+{p}_{I}{v}_{I,TL}\right)+{\dot{m}}_{2P}\left({u}_{I,2P}+{p}_{I}{v}_{I,2P}+\frac{{w}_{I,2P}^{2}}{2}\right),$$

where:

*Φ*is the energy flow rate at port_{TL}**TL**.*Φ*is the energy flow rate at port_{2P}**2P**.*u*is the specific energy of the thermal liquid at the internal node I._{I,TL}*p*is the pressure of the fluids at the internal node I._{I}*v*is the specific volume of the thermal liquid at the internal node I._{I,TL}*u*is the specific energy of the two-phase fluid at the internal node I._{I,2P}*v*is the specific volume of the two-phase fluid at the internal node I._{I,2P}*w*is the speed of the fluid on the two-phase fluid side at the internal node I:_{I,2P}$${w}_{I,2P}=\frac{{\dot{m}}_{2P}{v}_{I,2P}}{S},$$

where

*S*is the value of the**Cross-sectional area at ports 2P and TL**parameter.