Study on salt water modeling of gravity currents prior to backdrafts using flow visualization and digital particle image velocimetry

摘要

In order to investigate the speed and clarity of the extent of the mixed region of gravity currents prior to backdrafts in building fires, a series of scaled salt water experiments using flow visualization and digital particle image velocimetry were conducted. The scaled compartment (0.4 mx0.1 mx0.1 m) was fitted with a variety of end and ceiling opening geometries, respectively: full, middle-slot, upside-slot, downside-slot, door and window. The experimental results show that the gravity currents in salt water experiments are similar to other naturally occurring gravity currents. And the experiments can model the gravity currents prior to backdrafts in building fires and predict the time of ignition for backdrafts in compartments with the same opening geometries. [References: 14]