SHOCK-WAVES IN AN ELLIPTIC CAVITY WITH VARYING HEIGHT

Transient shock waves in a confined elliptical chamber are experimenta lly investigated. Quantitative results of the pressure distribution ar e obtained for an air-filled cavity. Lower bounding surfaces of differ ent geometrical shapes can be inserted making it possible to get chamb ers with varying height. An electrical discharge across a pair of elec trodes inside the cavity gives rise to the shock waves. Double pulsed holographic interferometry is used to study the propagation and focusi ng process of the waves. The results are quantitatively evaluated by u sing the method of two-reference-beam holography. The angular pressure distribution behind the converging wave front is presented for differ ent geometries of an air-filled cavity. The pressure distribution is n on-homogeneous but symmetric along the wave front. The pressure level is higher for the geometry where the height of the chamber decreases w ith the radial distance from the outgoing focus and lower for increasi ng height of the chamber. In addition, shock waves in a water-filled c avity are studied. In this case qualitative results are obtained.