Journal ArticleDOI
Detonation propagation in hydrogen-air mixtures with transverse concentration gradients
TLDR
In this paper, the influence of transverse concentration gradients on detonation propagation was investigated experimentally in a wide parameter range, and significant amounts of mixture seem to be consumed by turbulent deflagration behind the leading detonation.Abstract:
The influence of transverse concentration gradients on detonation propagation in $$\hbox {H}_2$$
–air mixtures is investigated experimentally in a wide parameter range. Detonation fronts are characterized by means of high-speed shadowgraphy, OH* imaging, pressure measurements, and soot foils. Steep concentration gradients at low average $$\hbox {H}_2$$
concentrations lead to single-headed detonations. A maximum velocity deficit compared to the Chapman–Jouguet velocity of 9 % is observed. Significant amounts of mixture seem to be consumed by turbulent deflagration behind the leading detonation. Wall pressure measurements show high local pressure peaks due to strong transverse waves caused by the concentration gradients. Higher average $$\hbox {H}_2$$
concentrations or weaker gradients allow for multi-headed detonation propagation.read more
Citations
More filters
Journal ArticleDOI
Chemiluminescence imaging of an optically accessible non-premixed rotating detonation engine
Brent A. Rankin,Daniel R. Richardson,Andrew W. Caswell,Andrew Naples,John Hoke,Frederick Schauer +5 more
TL;DR: In this article, the detonations propagating through the annular channel of an optically accessible rotating detonation engine (RDE) operating on hydrogen-air are visualized using OH* chemiluminescence imaging.
Journal ArticleDOI
Overview of Performance, Application, and Analysis of Rotating Detonation Engine Technologies
Brent A. Rankin,Matthew L. Fotia,Andrew Naples,Christopher A. Stevens,John Hoke,Thomas A. Kaemming,Scott W. Theuerkauf,Frederick Schauer +7 more
TL;DR: In this article, rotating detonation engines are compared to pulsed detonation engine and they are shown to produce thrust with fuel efficiencies similar to those associated with pulsed engines while operating on gaseous hydrocarbon fuels.
Journal ArticleDOI
Origin and chaotic propagation of multiple rotating detonation waves in hydrogen/air mixtures
Majie Zhao,Huangwei Zhang +1 more
TL;DR: In this article, the origin and chaotic propagation of multiple detonative waves in the two-dimensional modelled rotating detonation combustor fueled by premixed hydrogen/air mixtures are numerically investigated with detailed chemical mechanism.
Journal ArticleDOI
Investigation of the structure of detonation waves in a non-premixed hydrogen–air rotating detonation engine using mid-infrared imaging
TL;DR: In this article, the structure of the detonation wave propagating through the annular channel of an optically accessible non-premixed rotating detonation engine (RDE) is investigated using mid-infrared imaging.
Journal ArticleDOI
Counter-rotating wave mode transition dynamics in an RDC
TL;DR: In this paper, an experimental study on the transition dynamics in a hydrogen-air RDC as the operating mode transitions from two steadily propagating, equally-fast counter-rotating waves to a single wave depending on the operating condition is presented.
References
More filters
Journal ArticleDOI
Deflagration-to-Detonation Transition in Hydrogen/Air Mixtures with a Concentration Gradient
TL;DR: In this article, an injection mechanism was developed that produces vertical fuel concentration gradients inside a horizontal channel with large aspect ratio, equipped with obstacles to enhance flame acceleration, and Schlieren measurements were conducted to track gas mixing behind the obstacles and to track the formation of the detonation.
Journal ArticleDOI
The influence of a compressible boundary on the propagation of gaseous detonations
TL;DR: In this paper, the velocity decrement of a gaseous detonation propagating through a channel with a compressible, nonreacting boundary is investigated experimentally and theoretically.
Journal ArticleDOI
Behavior of detonation propagation in mixtures with concentration gradients
Kazuhiro Ishii,M. Kojima +1 more
TL;DR: In this article, the behavior of detonation waves in mixtures with concentration gradients normal to the propagation direction was studied experimentally, where a stoichiometric hydrogen-oxygen mixture was charged in the detonation chamber, while oxygen or nitrogen was filled in the diffusion gas chamber.
Journal ArticleDOI
Gas-phase detonation propagation in mixture composition gradients.
TL;DR: The propagation of detonations through several fuel–air mixtures with spatially varying fuel concentrations is examined numerically, finding that in the high-activation-energy mixture, detonations propagate more slowly as the magnitude of the mixture composition gradient is increased and can be quenched in a large enough gradient.
Journal ArticleDOI
Flame Acceleration in Hydrogen/Air Mixtures with Concentration Gradients
TL;DR: In this article, the influence of mixture composition gradients on flame acceleration was investigated in an entirely closed channel at laboratory scale, and it was shown that concentration gradients can lead to significantly stronger flame acceleration compared to homogeneous mixtures.