Environment
Environment objects contain settings that affect sound propagation, such as air and ground properties.
Environment objects are also the containers for Barrier objects.
Input Parameters
| Name | Data type | Unit | Comment |
|---|---|---|---|
| Library item | Lib. item | - | The library item for the environment. |
| Ground height | Number | m | The relative height between the ground and the top of the rail. Value must be negative, i.e. the ground is below the top of the rail. |
| Absorption model | Choice | - | The absorption model used in the calculations. Available options are: No ground, Rigid ground, Miki, Delany-Bazley, or Hamet-Bérengier. |
| Thickness | Number | m | The thickness of the ground layer. |
| Flow resistivity | Number | Pa.s/m2 | The flow resistivity of the ground layer. |
| Porosity | Number | - | The porosity of the ground layer. |
| Tortuosity | Number | - | The tortuosity of the ground layer. |
| Air temperature | Number | °C | The temperature of the air. |
| Density | Number | kg/m3 | The density of the air. |
| Speed of sound | Number | m/s | The speed of sound in air. |
| Custom graphics file | File | - | Custom background graphics can be added to the model; the file to use is specified here (with ’.xml’ file extension ). |