Parametric Study of an Explosive-Driven Shock Tube as Blast Loading Tool

The need for efficient blast loading tools is increasing with the development of new protective techniques. Among these tools, one can cite the use of an explosive-driven shock tube (EDST). The purpose of the present study is to define analytical equations to predict incident and reflected pressure and impulse generated at a laboratory scale EDST end in terms of the tube length, the tube diameter, the explosive mass, and the stand-off distance. The formulae are obtained based on a dimensional analysis and a numerical parametric study. The analytical study is supported by a set of experiments, in order to validate the obtained analytical models. The EDSTs discussed in this study are open on both sides with diameters ranging from 0.15 to 0.50m and a length ranging from 0.75 to 3m. Two different tube sections, circular, and square, are examined. Explosive charges from 5 to 50 g of C4 are used. Within these conditions reflected pressures ranging from 0.15 to 11 MPa and reflected impulses ranging from 100 to 3000 Pa·s are obtained at the tube end. The obtained analytical equations are compared to several available results and formulae from the literature. In addition to that, a graphic representation is developed in order to estimate the tube geometry and the explosive mass necessary to generate a given couple of pressure–impulse at the tube end.