# Controlled Trace Gas Source (MA)

Inject or extract trace gas at a time-varying rate

• Library:
• Simscape / Foundation Library / Moist Air / Sources / Moisture & Trace Gas Sources

## Description

The Controlled Trace Gas Source (MA) block represents a time-varying source or sink of trace gas for the connected moist air volume. Two physical signal input ports, M and T, supply the mass flow rate and temperature values, respectively. A positive or negative trace gas mass flow rate causes trace gas levels to increase or decrease, respectively.

The energy associated with the added or removed trace gas is

where:

• ${\stackrel{˙}{m}}_{specified}$ is the trace gas mass flow rate specified by the input physical signal at port M.

• hg is the trace gas specific enthalpy.

• Tspecified is the temperature of added trace gas specified by the input physical signal at port T. The block uses this value to evaluate the specific enthalpy of the added trace gas only. The specific enthalpy of removed trace gas is based on the temperature of the connected moist air volume.

• Ts is the temperature at port S, which is the same as the temperature of the connected moist air volume.

Port S is a moist air source conserving port. Connect this port to port S of a block with finite moist air volume to add or remove trace gas through that block. For more information, see Using Moisture and Trace Gas Sources.

## Ports

### Input

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Input physical signal that specifies the trace gas mass flow rate through the source.

Input physical signal that specifies the temperature of added trace gas. The block uses this value to evaluate the specific enthalpy of the added trace gas only. The specific enthalpy of removed trace gas is based on the temperature of the connected moist air volume.

### Conserving

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Connect this port to port S of a block with finite moist air volume to add or remove trace gas through that block.