Experimental investigation of cylindrical shock wave interactions

Shock focusing allows for concentration of energy in a specific area, and as a result, localized extreme conditions occur, such as high temperatures and pressures. Shock waves can undergo either regular or irregular reflections. The type of reflection generated significantly changes the properties behind the shock front. To obtain a high degree of control over the shock front, transition from regular and irregular reflections must be understood. To help further this understanding adequate experimental data is necessary. Particularly, the relationship between the shape of the shock and the properties, such as pressure, behind the shock front is of interest. In this study, experiments were conducted using an exploding wire setup for producing two synchronized cylindrical shock waves. Exploding wire setups provide rapid experiment iteration and exceptional cost-effectiveness compared to large-scale experiments or computational modeling. The data used for shock-shock interactions were collected via pressure sensors and ultra-high-speed Schlieren imaging. Experiments exhibited a high degree of repeatability, which allowed for the comparison of the peak pressures of the Mach stem be compared to that of the incident shock. It was concluded that the Mach stem exhibits peak pressures that are on average 24.92% ± 8.54% greater than the peak pressures of the incident shock, but decay faster. It was also determined that Mach reflections were only seen in cases where the Mach number exceeds approximately 1.45.