A Magnetic Annular Arc Driven Shock Type

摘要

The production of high speed shocks in shock tubes has been limited to levels below 1.3 CM/microsec by excessive radiation from the initially stagnant arc heated driver gas. This limitation can be removed by adding the required energy to a flowing driver gas in a device in which the static temperature is maintained at a sufficiently low level to keep the radiation losses small. It is shown that the only prerequisite for such a device is that it is capable of adding the required energy to a mass flow of driver gas sufficiently large as to keep the static temperature low. The magnetic annular arc (MAARC) has demonstrated such capabilities in applications for space propulsion and solar wind simulation. Based on this past experience, a MAARC driver has been constructed and tested on a 1-1/2 in. shock tube. The MAARC was operated at an average power level equal to 200 MW for 50 Microsec at a voltage of 1 KV. Helium was used as the driver gas and shock speeds in excess of 2 CM/Microsec were obtained in air. Several measurements were made to determine the test time which was found to be approximately 5 microsec at the above conditions. This figure agrees with what is to be expected from theoretical considerations. (Author)