TY - JOUR
T1 - Cell-like structure of unstable oblique detonation wave from high-resolution numerical simulation
AU - Choi, Jeong Yeol
AU - Kim, Dong Wan
AU - Jeung, In Seuck
AU - Fuhua, Ma
AU - Yang, Vigor
N1 - Funding Information:
Present work has been sponsored partly by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD) (KRF-2006-521-D00061), and the National Research Laboratory program (M10500000072-05J000007210) of Korea Science and Engineering Foundation.
Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2007
Y1 - 2007
N2 - A comprehensive numerical study was carried out to investigate the unsteady cell-like structures of oblique detonation waves (ODWs) for a fixed Mach 7 inlet flow over a wedge of 30° turning angle. The effects of grid resolution and activation energy were examined systematically at a dimensionless heat addition of 10. The ODW front remains stable for a low activation energy regardless of grid resolution, but becomes unstable for a high activation energy featuring a cell-like wave front structure. Similar to the situation with an ordinary normal detonation wave (NDW), a continuous increase in the activation energy eventually causes the wave-front oscillation to transit from a regular to an irregular pattern. The wave structure of an unstable ODW, however, differs considerably from that of a NDW. Under the present flow condition, triple points and transverse waves propagate downstream, and the numerical smoke-foil record exhibits traces of triple points that rarely intersect with each other. Several instability-driving mechanisms were conjectured from the highly refined results. Since the reaction front behind a shock wave can be easily destabilized by disturbance inherent in the flowfield, the ODW front becomes unstable and displays cell-like structures due to the local pressure oscillations and/or the reflected shock waves originating from the triple points. The combined effects of various instability sources give rise to a highly unstable and complex flow structure behind an unstable ODW front.
AB - A comprehensive numerical study was carried out to investigate the unsteady cell-like structures of oblique detonation waves (ODWs) for a fixed Mach 7 inlet flow over a wedge of 30° turning angle. The effects of grid resolution and activation energy were examined systematically at a dimensionless heat addition of 10. The ODW front remains stable for a low activation energy regardless of grid resolution, but becomes unstable for a high activation energy featuring a cell-like wave front structure. Similar to the situation with an ordinary normal detonation wave (NDW), a continuous increase in the activation energy eventually causes the wave-front oscillation to transit from a regular to an irregular pattern. The wave structure of an unstable ODW, however, differs considerably from that of a NDW. Under the present flow condition, triple points and transverse waves propagate downstream, and the numerical smoke-foil record exhibits traces of triple points that rarely intersect with each other. Several instability-driving mechanisms were conjectured from the highly refined results. Since the reaction front behind a shock wave can be easily destabilized by disturbance inherent in the flowfield, the ODW front becomes unstable and displays cell-like structures due to the local pressure oscillations and/or the reflected shock waves originating from the triple points. The combined effects of various instability sources give rise to a highly unstable and complex flow structure behind an unstable ODW front.
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U2 - 10.1016/j.proci.2006.07.173
DO - 10.1016/j.proci.2006.07.173
M3 - Conference article
AN - SCOPUS:34548772818
SN - 1540-7489
VL - 31 II
SP - 2473
EP - 2480
JO - Proceedings of the Combustion Institute
JF - Proceedings of the Combustion Institute
T2 - 31st International Symposium on Combustion
Y2 - 5 August 2006 through 11 August 2006
ER -