Hydrogen heating in the discharge chamber of powerful electric discharge launcher

Summary form only given, as follows. Results of the discharge chamber of an electric discharge launcher testing, aiming at a heat transfer study is presented. Test conditions are: initial H/sub 2/ pressure-5-40 MPa, discharge chamber volume-1400 cm/sup 3/, current /spl les/1.5 MA, energy stored-1.3 MJ, circuit own frequency-1 kHz. To simulate gas heating in the EDL discharge chamber and to use high speed camera, a diagnostic discharge chamber was made. Based on the arc dynamics study in the diagnostic discharge chamber, temperature and conductivity estimations of the arc channel were carried out for the EDL chamber. Measured pressure 200 MPa and conductivity 230 (/spl Omega//spl times/cm)/sup -1/ correspond to temperatures of (3.3-3.5)/spl times/10/sup 4/ K and of (2.3-2.4)/spl times/10/sup 4/ K for the arcs, burning respectively in copper vapor and in H/sub 2/. Real temperature seems to lie between these two values. Since the pressure equilibrium in the volume was reached, acoustic oscillations may be used to evaluate gas temperature. Moving arcs cause shock waves registered by pressure transducers, placed along discharge length, and by high speed camera. Arc-to-gas energy transfer efficiency rises along with initial H/sub 2/ pressure increase and reaches 90% for 40 MPa. Both shock wave propagation and arc radiation absorption contribute to this rise.