• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.314-318
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• 2006

The interest on the detonation in small tubes, which can be applied to the ignition devices of propulsion system, is increasing. However, the propagation dynamics of detonation waves in small tubes has not been investigated clearly yet. In the present experiments, propagations of detonation waves in stoichiometric propane-oxygen mixture through transparent tubes were recorded using a high speed camera and average velocities were measured as well. In terms of average velocity, there exists a transition regime where the waves show smooth transition from the normal Chapman-Jouguet(CJ) detonation to the low velocity detonation$(\sim0.5V_{CJ})$ along the decreasing initial pressure. In this transition regime, the detonation waves are highly unstable and show cyclic or intermittent longitudinal velocity fluctuation.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.3
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• pp.81-89
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• 2018

In this study, the operating characteristics of a small-scale pulse detonation engine (PDE) were investigated experimentally for application as a small thruster and an igniter. The PDE was constructed using commercial gas tubes with an inner diameter of 4.22 mm. The operating and detonation propagation characteristics of the PDE were investigated over the ranges of equivalence ratios and operating frequencies. Measured detonation speed was close to 10% of the theoretical CJ values at 1 Hz and 5 Hz conditions. However, unstable propagation characteristics were shown at 20 Hz and lean conditions, where the velocity deficit was increased by 20~62%.