FDS+Evac tools

FDS cell size

This tool allows users to determine the right size for the FDS cells according to McGrattan et al.(2010).

"For simulations involving buoyant plumes, a measure of how well the flow field is resolved is given by the non-dimensional expression D*/x, where D* is a characteristic fire diameter and x is the nominal size of a mesh cell."

In a sensitivity analysis (Hill et al., 2007), sponsored by the U.S. Nuclear Regulatory Commission, the D * / x value ranges between 4 and 16.

Cell size (x) [m]:
Heat Release Rate (Q) [kW]:
Air density (p) [kg/m3]:
Air thermal capacity (cp) [kJ/kg K]:
Ambient air temperature (T) [K]:
Gravitational acceleration (g) [m/s2]: