Marks, Brandon (2013-08). A New Facility for Studying Shock Wave Passage over Dust Layers. Master's Thesis.
To ensure safety regarding dust explosion hazards, it is important to study the dust lifting process experimentally and identify important parameters that will be valuable for development and validation of numerical predictions of this phenomenon. A new shock tube test section was developed and integrated into an existing shock tube facility. The test section allows for shadowgraph or laser scattering techniques to track dust layer particle motion. The test section is designed to handle an initial pressure of 1 atm with an incident shock wave velocity up to Mach 2 to mimic real world conditions. The test section features an easily removable dust pan and inserts to allow for adjustment of dust layer thickness. The design allows for the changing of experimental variables including initial pressure, Mach number, dust layer thickness and characteristics of the dust itself. A separate vacuum manifold was designed to protect existing equipment from negative side effects of the dust. A study was performed to demonstrate the capabilities of the new facility and to compare results with experimental trends formerly established in the literature. Forty-micron limestone dust with a layer thickness of 3.2 mm was subjected to Mach 1.22 and 1.38 shock waves, and a high-speed shadowgraph was used for flow visualization. Dust layer rise height was graphed with respect to shock wave propagation. Dust particles subjected to a Mach 1.38 shock wave rose more rapidly and to a greater height with respect to shock wave propagation than particles subjected to a Mach 1.22 shock wave. These results are in agreement with trends found in the literature, and a new area of investigation was identified.