Small-scale exploding wire experiments of blast wave propagation in tunnels

Underground storage of energetic materials in confined spaces, such as underground mining operations, requires safety considerations to ensure that workers, equipment and surrounding structures are safe in the case of an accidental explosion. If an accident were to occur, understanding of how the blast wave propagates and attenuates as it travels through tunnels and intersections will help with safety assessments. There are different ways to generate data for these types of scenarios ranging from full-scale to small-scale tests. While full-scale tests may provide more accurate information, small-scale tests are generally safer to perform, less expensive, less time consuming and more experiments can be performed. Small-scale tests may provide reasonable data given appropriate scaling techniques. In this work, three types of small-scale experiments utilizing exploding wires were used to generate side-on overpressure data and to gather schlieren photography. Results show that the exploding wire experiments are repeatable with standard deviations ranging from 29.5 kPa to 0.2759 kPa depending on the tunnel geometry and pressure sensor location. Finally, cube-root scaling laws with an energy concentration factor to account for the tunnel geometry were used to compare the present work to earlier published results using high explosives and results are reasonable.