Validating FDS Against a Large-Scale Fire Test for Facade Systems

In an MSc thesis conducted at Lund University, Sweden, a validation study of FDS version 6.2.0 on the area of external fire spread was conducted. The validation study was performed using experimental data from a large-scale fire test on an SP FIRE 105 test rig in Borås, Sweden. The SP FIRE 105 test rig is a test method for facade systems simulating the impact on the overhead facade of a fire on the ground floor of a three-story apartment building. For this particular test, non-combustible calcium silica boards were attached to the facade and temperature measurements took place at six different heights. A previous validation study for this setup has been conducted by SP using FDS version 5.5.3, showing promising results. However, as FDS is updated it does not automatically mean that every area is improved, and possible changes are important to address. Also, in the revision of the model from version 5 to version 6 changes were made in the basic turbulence model, meaning that a different result than the SP study was to be expected. The study concluded that FDS version 6.2.0 could reproduce the experimental results with a reasonable level of detail. Moreover, the studied output data produced in FDS 6.2.0 were generally higher than its precursor. However, to obtain credible results along the facade particularly close to the fire, a high mesh resolution was needed, namely a D^*/𝛿x of at least 30.