## Pneumatic Domain

Note

As of R2016b, the gas domain replaces the pneumatic domain as the recommended way of modeling pneumatic systems. The pneumatic domain definition is still provided with the software, for compatibility reasons. However, it can be removed in a future release.

The pneumatic domain declaration is shown below.

```domain pneumatic % Pneumatic 1-D Flow Domain % Copyright 2008-2013 The MathWorks, Inc. parameters gam = { 1.4, '1' }; % Ratio of specific heats c_p = { 1005 , 'J/kg/K' }; % Specific heat at constant pressure c_v = { 717.86 , 'J/kg/K' }; % Specific heat at constant volume R = { 287.05, 'J/kg/K' }; % Specific gas constant viscosity = { 18.21e-6, 'Pa*s' }; % Viscosity Pa = { 101325, 'Pa' }; % Ambient pressure Ta = { 293.15, 'K' }; % Ambient temperature end variables p = { 0 , 'Pa' }; T = { 0 , 'K' }; end variables(Balancing = true) G = { 0 , 'kg/s' }; Q = { 0 , 'J/s' }; end end ```

It contains the following variables and parameters:

• Across variable p (absolute pressure), in Pa

• Through variable G (mass flow rate), in kg/s

• Across variable T (temperature), in kelvin

• Through variable Q (heat flow), in J/s

• Parameter gam, defining the ratio of specific heats

• Parameter c_p, defining specific heat at constant pressure

• Parameter c_v, defining specific heat at constant volume

• Parameter R, defining specific gas constant

• Parameter viscosity, specifying the gas viscosity

• Parameter Pa, specifying the ambient pressure

• Parameter Ta, specifying the ambient temperature

These parameter values correspond to gas properties for dry air and ambient conditions of 101325 Pa and 20 degrees Celsius.

To refer to this domain in your custom component declarations, use the following syntax:

`foundation.pneumatic.pneumatic `