PhD Oral Exam - Chian Yan, Mechanical Engineering

When studying for a doctoral degree (PhD), candidates submit a thesis that provides a critical review of the current state of knowledge of the thesis subject as well as the student’s own contributions to the subject. The distinguishing criterion of doctoral graduate research is a significant and original contribution to knowledge.

Once accepted, the candidate presents the thesis orally. This oral exam is open to the public.

Abstract

Detonation is a supersonic, self-sustained, combustion-driven wave. Real detonation wavefronts are inherently unstable, and their structures are unsteady with different levels of instabilities embedded at the frontal structure. To elucidate the effects of instabilities on various dynamics of the detonation wave, such as its initiation, failure, and propagation mechanism, this thesis research proposes a series of numerical investigations by perturbing the unstable detonation structure from mixture inhomogeneity, boundary conditions, and an external obstacle to increase flow instability artificially. Through these studies of different scenarios, the significance of the instabilities of the unstable detonation front structure on the detonation dynamics and critical phenomena would be conclusively demonstrated, and the results contribute to a better understanding of gaseous detonation behaviour.