Showing papers in "Proceedings of the Combustion Institute in 2022"

TL;DR: In this paper , a review of recent progress in plasma-assisted combustion with a special focus on flame dynamics is presented and an additional level of complexity is introduced by considering the effect of such plasmas on the coupling between flames and acoustic waves.

TL;DR: In this article , a series of turbulent premixed ammonia/hydrogen/air flames were investigated using the NH-PLIF diagnostics, and three correlations for the ST,GC were developed based on Damkohler's second hypothesis with consideration of the Le effect.

TL;DR: In this article , the sustainability and combustion performance of binary mixtures of ammonia and low-molecular-weight alcohols in a cyclonic burner were analyzed, where MILD conditions were attained by means of a strong internal recirculation, and compared with those obtained with NH3/methane blends.

TL;DR: In this paper , a quantitative manifold-informed method for selecting the subset of state variables that minimizes unwanted behaviors in manifold topologies is presented, where a mixture of major and minor species can be beneficial to improving the quality of low-dimensional data representations.

TL;DR: In this article , the effects of ozone addition on the laminar burning velocity of premixed NH3/(35%O2/65%N2) and NH3+ CH4/C2H6/C3H8+air flames over a wide range of equivalence ratios were investigated experimentally and numerically.

TL;DR: In this paper , a new chemical kinetic mechanism for NH3/C2H5OH mixtures was developed and it was highlighted that the addition of cross-reactions between the two fuels is necessary to obtain reasonable simulations.

TL;DR: In this article , a detailed kinetic model was developed by systematically updating rate constants of controlling reactions and declaring new reactions for N2H2 isomers (cis and trans) for low-temperature conditions.

TL;DR: In this paper , the effect of ammonia (NH3) addition on soot growth and inception was investigated in laminar co-flow NH3-ethylene (C2H4) diffusion flames.

TL;DR: In this article , the effects of non-equilibrium nanosecond plasma discharge pulse repetition frequency, pulse number, and flow velocity on the critical ignition volume, minimum ignition energy, and chemistry in a plasma-assisted H2/air flow at 300 K and 1 atm using a multi-scale adaptive reduced chemistry solver for plasma assisted combustion (MARCS-PAC).

TL;DR: In this article , a single-stage swirl burner was used to experimentally investigate the effects of residence time on emissions from premixed ammonia-methane-air flames, and the results showed that increasing residence time can further advance chemical reactions, as evidenced by a reduction in O2 concentration in the exhaust.

TL;DR: In this paper , the effects of NRPDs on the second stage flame of a sequential combustor were investigated using numerical tools supported by experiments, and the results of the LESs were analyzed to explain the underlying physics.

TL;DR: In this article , the authors introduced two non-premixed turbulent jet flames that emulate some features of the cracked ammonia combustion at 5 bar, relevant to micro gas turbines, which are particularly amenable to modeling.

TL;DR: In this article , the effects of curvature on the local heat release rate and mixture fraction during turbulent flame-wall interaction of a lean dimethyl ether/air flame using a fully resolved simulation with a reduced skeletal chemical reaction mechanism and mixture-averaged transport were investigated.

TL;DR: In this paper , a fundamental investigation of the H-abstraction reactions from H2NO by O2, NO2, NH2, and HO2 was performed, and the obtained rates were integrated into a kinetic model, which was used to investigate ammonia oxidation and ignition at low-temperature and oxygen-rich conditions.

TL;DR: In this article , 3D detonation simulations solving the compressible Navier-Stokes equations with detailed chemistry are performed in both square channel and round tube geometries, and the results show that 3D explosions propagate with highly inhomogeneous blast dynamics.

TL;DR: In this article , a new comprehensive kinetic model for NH3/CH4 mixtures oxidation was developed based on the previous work and evaluated against the ignition delay times, laminar flame speeds, and species profiles of pure ammonia and ammonia/methane mixtures.

TL;DR: In this paper , the co-firing characteristics of ammonia with pulverized coal are studied in a drop tube furnace with staged combustion strategy, and it was shown that staged combustion would play a key role in reducing NOx emissions by reducing the production of char-NOx and fuel(NH3)-NOx simultaneously.

TL;DR: In this paper , a universal detonation response diagram with multiple, non-monotonic boundaries of auto-ignition modes under engine-relevant conditions is presented, and two detonation peninsulas are identified, with the first corresponding to the well-established Bradley detonation peninsula and the second manifesting a broader detonation regime.

TL;DR: In this article , the authors explore the hydrodynamic instability characteristics of several key combustor unit flows (wakes, swirling jets, etc.) and show how hydrodynamics stability of a flow is an important consideration in determining a combustor's propensity for thermoacoustic oscillations.

TL;DR: In this paper , the authors investigated the co-combustion behaviors of NH3 and a high-volatile coal on a two-stage flat flame burner and proposed a characteristic time scale τOH from the OH signals for the initiation of overall reactions in the system.

TL;DR: In this article , direct numerical simulations of lean hydrogen flame kernels under engine conditions have been performed to investigate how differential diffusion affects their growth with an effective Lewis number far smaller than unity and if thermodiffusive instabilities appear under realistic engine conditions with elevated in-cylinder pressure and high unburned temperature.

TL;DR: In this article , an atmospheric pressure laminar premixed methane/air mixture by Nanosecond Repetitively Pulsed (NRP) discharges in a pin-pin configuration is studied using fully coupled plasma-combustion numerical simulations.

TL;DR: In this paper , a review of recent progress with respect to biomass pyrolysis properties, the pyrolys process, and product upgrading strategies focusing on carbon-based high-value liquid fuels and carbon-bearing materials are summarized.

TL;DR: In this paper , the contribution of each instability mechanism is quantified separately by performing detailed simulations of laminar planar lean hydrogen/air flames with different diffusivity models and equations of state to selectively suppress the hydrodynamic or thermodiffusive instability mechanism.

TL;DR: In this article , the UV and visible chemiluminescence signatures of laminar ammonia-hydrogen-air flames were investigated and a counterflow burner was used to stabilize flat and steady premixed ammonia and hydrogen-air twin-flames for wide ranges of ammonia fuel fractions (0.55≤XNH3≤0.90), equivalence ratios ( 0.35≤ϕ≤1.70), and strain rates (50≤a≤300/s).

TL;DR: In this paper , the effect of nano-second pulsed non-equilibrium plasma on ammonia combustion in a model gas turbine combustor using NH2* chemiluminescence and OH planar laser-induced fluorescence (PLIF).

TL;DR: In this article , the size evolution and temperature of laser-ignited iron particles in a narrow size range around 45-55μ m were monitored by a high-speed shadowgraphy system, and the particle temperature was probed using a two-color pyrometer synchronized with the shadow graph system.

TL;DR: In this article , the NH3/H2 experiments were conducted over a wide range of temperatures (1474-2307 K), near-atmospheric pressure, near-stoichiometric NH3:H2 ratios of 80:20 and 50:50, respectively.

TL;DR: In this paper , the current state and challenges of advanced experimental and modeling methods for a better understanding of heterogeneous chemical reactions are discussed using examples from developing and future technologies in the area of emission reduction of local pollutants and greenhouse gases.

TL;DR: In this article , the feasibility of co-firing NH3 with coal and biomass in a 25 kW down-fired furnace with a swirl-stabilized burner was investigated, where NH3 was injected from the central tube at thermal ratios ranging from 0 to 30%.