Constant volume pneumatic chamber based on ideal gas law
The Constant Volume Pneumatic Chamber block models a constant volume pneumatic chamber based on the ideal gas law and assuming constant specific heats.
The continuity equation for the network representation of the constant chamber is
|G||Mass flow rate at input port|
|p||Absolute pressure in the chamber|
|R||Specific gas constant|
|T||Absolute gas temperature|
The equivalent circuit of the Constant Volume Pneumatic Chamber block model is shown in the following illustration. Port A is the pneumatic conserving port associated with the chamber inlet. Port A connects both to the gaseous and the thermal circuit. Port H is a thermal conserving port through which heat exchange with the environment takes place. Port H connects only to the thermal circuit.
The diagram shows that the heat flow q to the chamber consists of two components:
Heat flow qCH, associated with the gaseous process
Heat flow qHE, associated with the heat exchange with the environment
The heat flow due to gas inflow is
where cv is specific heat at constant volume.
The heat exchange with the environment happens through port H, connected to thermal components. To determine the value of the heat exchange flow, the model contains a short-circuit element, resulting in the equation
TA = TH
where both TA and TH represent the gas temperature.
The gas flow and the heat flow are considered positive if they flow into the chamber.
The gas is ideal.
Specific heats at constant pressure and constant volume, cp and cv, are constant.
Specify the volume of the chamber. The default value is .001 m^3.
Specify the initial pressure in the chamber. This parameter specifies the initial condition for use in computing the initial state at the beginning of a simulation run. For more information, see Initial Conditions Computation. The default value is 101235 Pa.
Specify the initial temperature of the gas in the chamber. This parameter specifies the initial condition for use in computing the initial state at the beginning of a simulation run. For more information, see Initial Conditions Computation. The default value is 293.15 K.
The block has the following ports: