Quantitative salt-water modeling of fire-induced flow

摘要

The dispersion of salt water carefully introduced into fresh water closely simulates the dispersion of hot exhaust gases in fire plumes. The salt concentration downstream of the source and exhaust gas temperature downstream of the flame zone behave like passive scalars and are transported by similar turbulent convective and diffusive processes. Transport properties of buoyant plumes are investigated through quantitative visualization of the distinctive turbulent structures responsible for dispersion in these flows. Turbulent mixing patterns are visualized via Planar Laser Induced Fluorescence (PLIF). This technique uses a laser light sheet to excite a fluorescent dye tracer suspended in the salt-water solution allowing visualization of a particular plane of the flow. The intensity of the fluorescence is proportional to the concentration of the salt water providing quantitative instantaneous field measurements of flow dispersion. Canonical flows including the unconfined plume and the impinging plume are carefully characterized and compared with fire scaling laws and fire measurements to validate the quantitative implementation of the PLIF salt-water technique.