Parametric study of an explosive driven shock tube: Experimental, analytical and numerical studies

The study of blast effects on structures as well as the assessment of the dynamic behaviour ofbuilding materials asks for experimental tools. Real scale experiments have important logistic andsecurity restrictions and ask for significant quantities of explosives in order to get the wantedpressure-impulse combinations. The size of real scale explosion analysis may be reduced by theexploitation of phenomena such as the confinement of the blast and the guidance of the blast wavetowards the target, by means of a tubular set-up. The present paper explores the idea of using anexplosive driven cylindrical shock tube in order to obtain selected combinations of peak pressuresand impulses.The paper first presents a dimensional analysis aiming to set up a model for the determination of thepressure and impulse as a result of an explosion at the entrance of the cylindrical tube. The modelstake into account several important parameters: the tube length and section, the explosive mass andthe charge-entrance distance. The models give rise to results which are assembled in easy to useabaci, which permit to evaluate the sensitiveness of the model for the different parameters.The analytical study is supported by a set of experiments, in order to validate the analytical models.The experimental and analytical results show good agreement and may serve for numerical modelvalidation.