Publication Date:
2020-10-06
Description:
This work presents a numerical study of detonation initiation by means of a focusing shock wave. The investigated geometry is a part of a pulsed detonation combustion chamber, consisting of a circular pipe in which the flow is obstructed by a single convergent–divergent axisymmetric nozzle. This obstacle acts as a focusing device for an incoming shock wave, serving as a low-energy detonation initiator. The chamber is filled with stoichiometric premixed hydrogen-enriched air. The simulation uses a one-step chemical model with variable parameters optimized by the adjoint approach in terms of the induction time $$au _{ext {c}}$$ τ c . The model reproduces $$au _{ext {c}}$$ τ c of a complex kinetics model in the range of pressures and temperatures appearing at the focusing point. The results give a comprehensive description of the shock-induced detonation initiation, which is the mechanism for the deflagration-to-detonation transition in this type of configurations. Potential geometry design improvements for technical applications are discussed. The first attempt to parameterize the transition process is also undertaken.
Print ISSN:
0938-1287
Electronic ISSN:
1432-2153
Topics:
Physics
,
Technology
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