Propagation of Curved Detonation Waves Stabilized in Annular Channels with a Rectangular Cross-section
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Visualization experiments employing rectangular cross-section curved channels were performed in order to examine the fundamental characteristics of a curved detonation wave propagating stably through an annular channel. A stoichiometric ethylene-oxygen mixture gas and five types of curved channels with different inner radii of curvature were used. The detonation waves propagating in the curved channels were curved due to the expansion waves from the inner walls of the curved channels. The ratio of the inner radius of curved channel (<i>r</i>i) to the normal detonation cell width (<i>λ</i>) was an important factor determining the stability of the curved detonation waves. The detonation propagation mode in the curved channels transitioned from unstable to stable in the range 14 ≤ <i>r</i>i/<i>λ</i> ≤ 26. The normal detonation velocity (<i>D</i>n) of the curved detonation wave propagating stably in a curved channel was approximately formulated. The approximated <i>D</i>n given by the formula agreed well with the experimental results. The front shock shape of the curved detonation wave could be reconstructed accurately using the formula. The value of <i>D</i>n nondimensionalized by the Chapman-Jouguet detonation velocity became a function of the local curvature of the curved detonation wave (<i>κ</i>) nondimensionalized by <i>λ</i> regardless of the shape of curved channel. The front shock shapes of the detonation waves in the stable mode became similar to each other under constant <i>r</i>i/<i>λ</i> conditions.
- TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN 10(ists28), Pe_7-Pe_14, 2012
THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES