円錐型電磁衝撃波管に関する研究

Abstract

Using conical type electromagnetic shock tubes, shock waves and luminous phenomena were observed with a rotating camera and a photomultiprier.Shock speeds were found to be in proportion to a factor V/√P0 for the observed ranges of initial pressure (P0) from 0.1 to 10mmHg and of discharge voltage (V) from 12 to 24kV. This result agrees qualitatively with the result of a simple analytical consideration based on a pinch expansion model.Two different motions due to shock waves and luminous fronts should be distinguished in the electromagnetic shock tube. Incident shock waves especially observed at low initial pressures below 1mmHg were obscured by luminous fronts, so that thermodynamical properties behind the shock wave should be estimated by those of the luminous region.A typical shock wave in the electromagnetic shock tube was followed by a local luminous region which was heated by the shock wave itself and had various lengths from 10 to 20cm in our experiments. This means that theR ankine-Hugoniot relations can not be used without any modifications.The reflections as many as twelve were recognized at an initial pressure of 6mmHg.