Mitigation of threats posed by transportation and storage of hazardous chemicals or defeat of targets containing biological and chemical agents requires basic investigations to characterize aerosol formation and dispersion. Advanced laser-based instrumentation are proposed that will be used to characterize the aerosol and gas phase dispersion of chemicals during an accidental or explosive release. These instruments will be hardened to withstand the explosive forces, high pressures, high temperatures, and the corrosive/reactive environment. A newly developed high speed imaging (HSI) system using pulsed diode lasers and digital imaging is proposed as a means to enable examination and characterization of the initial stages of the chemical release, disruptive boiling, and transient aerosol formation and evaporation. Advanced image processing algorithms will be used to provide qualitative and quantitative information on the spray and aerosol formation and droplet size. The phase Doppler interferometry (PDI) method will be used to characterize the aerosol size and velocity information providing quantitative measurements of the droplet dynamics. The PDI method is also capable of measuring vapor and gas phase mean and turbulence intensity, information that is critical to developing computational models to describe these events. Multiple instruments will be used to obtain temporal and spatial information.
