A Combustion-Driven Miniature Shock Tube with In-Situ Oxyhydrogen Generation: Energy and Impulse Analysis

This study investigates blast waves generated by an oxyhydrogen-driven combustion tube at varying fill pressures (14, 16, and 18 psi) and tube lengths (50 mm, 100 mm, and 150 mm). The primary purpose of varying these parameters is to establish a correlation between tube length and energy released. An electrolyzer-powered combustion tube is used to generate the blast waves. High-speed cameras use a Z-type Schlieren configuration to capture the blast wave’s evolution at 100,000 frames per second. After obtaining the Schlieren frames, a MATLAB code was developed to track the shock wave position, fit a radius curve using Dewey’s theory [1] and estimate the energy released using Jones’s blast trajectory theory [2]. The evolution of the blast wave is shown in the results, where a toroidal vortex forms as a result of lateral expansion. The 50 mm tube length causes a reflection from the closed end that distorts the blast front’s spherical shape. Additionally, the energy estimated from the blast trajectory theory indicates a peak value of 3.48 J for the 150 mm tube at a fill pressure of 18 psi. Future work will focus on analyzing the energy and impulse generated at the different fill pressure conditions to develop correlations.