Flow Rate Sensor (2P)

Measure mass, energy, and volumetric flow rates in two-phase fluid networks

Since R2023a

• 

Libraries:
Simscape / Foundation Library / Two-Phase Fluid / Sensors

Description

The Flow Rate Sensor (2P) block represents an ideal sensor that measures mass flow rate, energy flow rate, and volumetric flow rate in a two-phase fluid network. There is no change in pressure or temperature across the sensor.

Because the flow rates are Through variables, the block must connect in series with the component being measured.

The relative orientation of ports A and B establishes the measurement sign. The sign is positive if flow occurs from port A to port B. Switching port connections reverses the measurement sign.

Three physical signal ports are available to output the measurement data:

• Port M outputs the mass flow rate.

• Port V outputs the volumetric flow rate.

• Port φ outputs the energy flow rate.

These ports have conditional port visibility on the block icon. Use the block parameters to expose only the ports that you need for measurements in a particular model.

Connect the measurement ports to PS-Simulink Converter blocks to transform the output physical signals into Simulink^® signals, for example, for plotting or additional data processing.

Examples

Two-Phase Fluid Refrigeration

Models a vapor-compression refrigeration cycle using two-phase fluid components. The compressor drives the R-134a refrigerant through a condenser, an expansion valve, and an evaporator. The hot gas leaving the compressor condenses in the condenser via heat transfer to the environment. The pressure drops as the refrigerant passes through the expansion valve. The drop in pressure lowers the saturation temperature of the refrigerant. This enables it to boil in the evaporator as it absorbs heat from the refrigerator compartment. The refrigerant then returns to the compressor to repeat the cycle. The controller turns the compressor on and off to maintain the refrigerator compartment temperature within a band around the desired temperature.

• Open Model

Ports

Output

M — Mass flow rate measurement, kg/s

physical signal

Physical signal output port for mass flow rate measurement.

Dependencies

To enable this port, select the Mass flow rate check box.

V — Volumetric flow rate, m^3/s

physical signal

Physical signal output port for the volumetric flow rate measurement.

Dependencies

To enable this port, select the Volumetric flow rate check box.

φ — Energy flow rate measurement, W

physical signal

Physical signal output port for energy flow rate measurement.

Dependencies

To enable this port, select the Energy flow rate check box.

Conserving

A — Sensor inlet

two-phase fluid

Two-phase fluid conserving port. Flow rates are positive if fluid flows from port A to port B.

B — Sensor outlet

two-phase fluid

Two-phase fluid conserving port. Flow rates are positive if fluid flows from port A to port B.

Parameters

Mass flow rate — Control output port visibility for measuring mass flow rate

On (default) | Off

Selecting this check box exposes the output port M, which lets you measure mass flow rate.

Volumetric flow rate — Control output port visibility for measuring volumetric flow rate

Off (default) | On

Selecting this check box exposes the output port V, which lets you measure volumetric flow rate.

Energy flow rate — Control output port visibility for measuring energy flow rate

On (default) | Off

Selecting this check box exposes the output port φ, which lets you measure energy flow rate.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2023a

R2023a: Usability enhancement for thermal liquid sensors

In R2023a, separate Mass & Energy Flow Rate Sensor (2P) and Volumetric Flow Rate Sensor (2P) blocks have been combined into a single Flow Rate Sensor (2P) block that lets you measure mass flow rate, energy flow rate, and volumetric flow rate. The new block lets you use the block parameters to expose only the ports that you need for measurements in a particular model, which helps to reduce clutter and improve the block diagram layout.

This change has no compatibility impact when you use these Foundation library blocks in your models. When you open an existing model, the Mass & Energy Flow Rate Sensor (2P) and Volumetric Flow Rate Sensor (2P) blocks within it are automatically replaced by Flow Rate Sensor (2P) blocks with the appropriate ports exposed.

However, if you use the Mass & Energy Flow Rate Sensor (2P) and Volumetric Flow Rate Sensor (2P) blocks in your custom composite components, you need to update the composite component code.

Sensor Block to Update	Old Syntax	New Syntax
Mass & Energy Flow Rate Sensor (2P)	sensor = foundation.two_phase_fluid.sensors.mass_flow_energy_flow_sensor;	sensor = foundation.two_phase_fluid.sensors.flow_sensor;
Volumetric Flow Rate Sensor (2P)	sensor = foundation.two_phase_fluid.sensors.volumetric_flow_sensor;	sensor = foundation.two_phase_fluid.sensors.flow_sensor(volumetric_flow_measure=true);