ORCID

https://orcid.org/0009-0007-6005-0287

Keywords

Detonation, High-speed imaging, Hypersonics, Near-limit detonations

Abstract

The usage of detonation waves in hypersonic propulsion engines has seen substantial advancement in recent decades. The near-limit transition and failure process are key in these applications controlling the operability regime. The common cellular propagation of detonation waves fails in the near limit leading eventually to a singular transverse shock instability. The local dynamics of the wave causing this transition and the details of this singular instability remain a challenging question. These dynamics are examined in a fully automated detonation experiment using ultra-high-speed diagnostics and statistical analysis. Hydrocarbon fuel–oxidizer mixtures with nitrogen dilution are used to explore transition behavior over varied reactivity levels. Results show that near the limit, detonation support shifts from cellular instabilities to detonative transverse waves in irregular detonations. Four propagation modes are identified based on the presence and dominance of these waves. Regular detonations are shown to not form transverse detonations and do not have intermediate propagation modes. The formation and failure processes of transverse detonations are discussed, and the statistical behavior is analyzed. Detailed analysis shows the transverse detonations comprise a complex shock and slip-line structure. A triple-shocked high-pressure zone prevents front expansion, providing reinforcement to sustain the wave front. This structure mirrors that of the stabilized Oblique Detonation Wave (ODW). The initiation mechanism is investigated, and the deflagration-to-detonation transition behavior associated with the ODW is discussed.

Completion Date

2026

Semester

Spring

Committee Chair

Ahmed, Kareem

Degree

Doctor of Philosophy (Ph.D.)

College

College of Engineering and Computer Science

Department

Mechanical and Aerospace Engineering

Document Type

Dissertation/Thesis

Identifier

DP0053294

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