Shock tube studies of gaseous detonation waves

Abstract

The investigation is divided into two parts. 1. An investigation into the possibility of employing a microwave interferometer method, as used by Schultz and Pennelegion for strong shock waves in argon, for continuously monitoring the velocity of a detonation wave in a shock tube was made. The observation that the microwave reflection from the ionised gas behind the detonation front was more copious than expected, initiated a more thorough study of the electrical conductivity of detonation waves. Microwave absorption and Faraday rotation techniques were employed as well as D. C. probe or Langmuir probe methods and Lin’s magnetic interaction method. It is concluded that tube wall effects modify the electrical conductivity behind a detonation wave propagated in a shock tube. 2. A soot track method, as used by Denisov and Troshin and by Duff, was employed to study wave instabilities in detonations in 2H2 + O2 in a 2 in. diameter tube, at initial pressures below 200 torr. The resulting patterns yielded values of spin frequencies which gave complete correlation with pressure pulsations observed in pressure measurements at the same initial pressures. The pressure pulsations were therefore attributed to spin. The discovery by White that it was possible to create a detonation at low pressure which is not complicated by discontinuities in the wave front led to pressure measurements using the arrangement of White, to try and resolve a pre-reaction induction zone behind the shock pressure jump was observed. However no induction zone was observed mainly because the waves were too strongly overdriven, resulting in chemical reaction being initiated without sufficient delay to show up on the pressure record.

Date of Award	1964
Original language	English
Awarding Institution	Aberystwyth University
Supervisor	D. H. Edwards (Supervisor)