Our primary references for FDS implementation and experimental validation are: The FDS User’s Guide ( McGrattan et al.

In particular, we want to ensure that the new PyroSim Results Viewer correctly reads FDS results and displays smoke correctly. In this post we aim to describe and present some background on how visibility and obscuration are calculated in FDS, the core computation engine used in PyroSim. The calculated visibility is often used as an occupant tenability requirement, while obscuration is used to display smoke visually.

Visibility is the distance that an observer can identify an object relative to the background and obscuration is the amount that light intensity is reduced as it passes through smoke. The comparison of VTT experimental images with predicted smoke visualization using PyroSim/FDS shows remarkably good correlation. This post reviews how visibility is calculated in FDS, compares the calculation to experimental data, and discusses how smoke is visualized in the new PyroSim Results Viewer and in Smokeview. Smoke visibility and obscuration are critical outputs of a fire simulation. To follow along with this tutorial, download the relevant files here. VTT Experimental Validation of Visibility Created with software version: 2020.1 Table of Contents

Pyrosim fds