Diagnostics for liquid dispersion due to a high-speed impact with accident or vulnerability assessment application

The high-speed impact and subsequent dispersion of a large liquid slug is of interest for assessing vulnerability of structures when subjected to such an event. The Weber number associated with such liquid impacts is generally between 10 ⁵ and 10 ⁸. Because of the experiment scale and destructive nature of these high-energy impacts, most traditional diagnostics are difficult to implement. Therefore, unique diagnostics were employed in several tests to gather information on impact force, spreading instability, slug break-up, ejection velocity, droplet deformation and spray characteristics. Measurement techniques discussed here include high-speed photometrics, particle image velocimetry (PIV), TrackEye particle analysis, speckle correlation, single-pass schlieren imaging, phase Doppler particle analyzer (PDPA) and load cell measurements as applied to large-scale, high-speed liquid impacts.