Data concerning smoke concentration and visibility can be imported from computational fluid dynamics (CFD) simulations in two forms:
- Isosurfaces of smoke concentration (or any other variable desired) as VRML files or FDS isosurface files, which are visual in nature and do not affect the movement of people.
- Sample planes (on a uniform Cartesian mesh) of any CFD variable. Visibility data imported in this way can be used to modify the walking speed of people based on Jin and Yamada’s experimental data, or other data specified by the user. Sample planes of any other data variable can also be imported into STEPS.
The data import is quite general in nature and can be used with any CFD code or post-processor which allows extraction of VRML data and sample planes (typically carried out using the relevant CFD post-processing software, e.g. CFX-Post). It can be used in combination with both Ansys CFX (Versions 4, 5 and later) and Fluent, among others.
The following features are available in STEPS:
- Import of geometry and smoke data from the NIST Fire Dynamics Simulator (FDS)
- Import of geometry and data from the CFAST zone model
Fractional effective dose (FED) calculations
By first importing smoke data information from FDS or CFX, the total accumulated exposure dose data for any toxic element can be exported from STEPS for each individual in the simulation. STEPS uses the information from the automatically created Sample Planes to assign the appropriate concentration values.