Showing papers in "Combustion and Flame in 2020"

TL;DR: In this paper, the authors used Particle Image Velocimetry (PIV) and Planar Laser Induced Fluorescence (PLIF) imaging, in addition to Fourier Transform Infrared (FTIR) gas analysis to study the flow field, flame structure and emissions characteristics of a micro gas turbine swirl combustor fuelled with CH4 NH3-air mixtures.

TL;DR: In this article, the CRECK core model is developed upon the Aramco 2.0 mechanism and further extended the validation objectives to MILD and OXY fuel combustion conditions.

TL;DR: In this article, the NH3/syngas/air flames were co-firing with syngas to overcome the high ignition energy and low burning velocities of pure NH3 flames.

TL;DR: In this paper, the laminar burning velocities (SL) of NH3/syngas/air, NH 3/CO/air and NH 3 /H2/air premixed flames were performed by the heat flux method at pressures up to 5 atm.

TL;DR: In this paper, a three-component parallel reaction mechanism and a moisture model embedded into the pyrolysis model is proposed, wherein the reaction kinetic parameters are optimized by shuffled complex evolution algorithm.

TL;DR: In this paper, the authors explored the effect of differing inlet and outlet boundary conditions on the operation and performance of a rotating detonation combustor (RDC) over an annulus mass flux range of 50 to 210 kg s − 1 m − 2 and equivalence ratios of 0.7, 1.0, and 1.3.

TL;DR: In this article, NH3/CH4 mixtures with CH4 fractions of 0, 5, 10% and 50% were measured in a rapid compression machine at equivalence ratio φ = 0.5, pressures from 20 to 70 bar and temperatures from 930 to 1140 K.

TL;DR: In this article, the laminar burning velocity SL of NH3/air mixtures has been measured at unburnt gas temperature Tu from 298 K to 448 K, covering equivalence ratios from 0.85 to 1.25 and at 1 atm using the heat flux method.

TL;DR: In this paper, a modified fictitious diluent gas method was proposed to separate the chemical and thermal effects of syngas addition, which showed that the chemical effect was more responsible for the enhanced laminar flame propagation.

TL;DR: In this article, the influence of pressure on the combustion characteristics (i.e., ignition, volatiles combustion, char combustion) of a single lignite particle was investigated in a pressurized visualized fluidized bed combustor under O 2 N 2 and O 2 CO 2 atmospheres.

TL;DR: In this paper, the authors investigated pore structure, free radical concentrations, thermal behavior and FTIR micro-characteristics of the re-oxidation coal, using Scanning Electron Microscope (SEM), Electron Spin Resonance (ESR), Fourier Transform Infrared Spectroscopy (FTIR), and a Synchronous Thermal Analyzer (STA), and concluded that the extension of pores and micropores on the coal surface due to initial oxidation, lead to an increase in the combination of coal and O2 in the reoxidation of coal (

TL;DR: In this article, the substitution of aluminum particles with metallic alloys in order to reduce agglomeration in aluminized propellants was investigated, and a qualitative phenomenological mechanism was proposed based on a competition among four distinct effects: the metal melting temperature, the adhesive force of the aggloomerates, the propellant burning rate, and micro-explosions.

TL;DR: In this paper, a single-pulse shock tube study of pyrolysis of 2% C2-C6 1-alkenes is presented at 2 bar in the temperature range 900-1800 K.

TL;DR: In this paper, numerical simulations were conducted to study the flame acceleration and deflagration-to-detonation transition (DDT) in a channel with a bank of aligned obstacles.

TL;DR: In this article, the impact of hydrogen addition on the dynamics of a methane-air premixed flame is explored for different injection strategies, and the results indicate that pure hydrogen injected in minute fractions may be used as an efficient passive control means to mitigate combustion instabilities, but a compromise needs to be made with emissions.

TL;DR: In this article, a chemistry reduction approach based on machine learning is proposed and applied to direct numerical simulation (DNS) of a turbulent non-premixed syngas oxy-flame interacting with a cooled wall.

TL;DR: In this article, a laminar counterflow flame configuration with ethylene fuel mixed with different proportions of ammonia (between 0 and 25% by mole while the remainder is nitrogen) was measured using planar laser induced incandescence (PLII).

TL;DR: In this article, a new kinetic model for the prediction of the oxidation behavior of dimethyl ether and dimethoxymethane in freely propagating and burner stabilized premixed flames, in shock tubes, rapid compression machines, flow reactors, and a jet-stirred reactor has been developed.

TL;DR: In this article, the effects of direct-injection fuel properties types and proportion on late-injective RCCI strategy on a light-duty optical engine using multiple optical diagnostic techniques were investigated.

TL;DR: In this paper, the initial reaction of lignin pyrolysis was explored in depth with light gas emission combined with liquid bio-oil composition and physical-chemical structure of solid bio-char.

TL;DR: In this article, the authors investigated the effect of NH3 addition on the low-temperature autoignition of n-heptane and found that the NH3 fraction increased the total and first-stage ignition delay times.

TL;DR: In this paper, a hieratically-structured and high-performance CuO@TiO2−Al2O3 oxygen carrier was investigated in the context of chemical looping combustion (CLC) and chemical LOI with oxygen uncoupling (CLOU).

TL;DR: In this article, a finite-rate chemistry large-eddy simulation (LES) solver is utilized to investigate dual-fuel (DF) ignition process of n-dodecane spray injection into a methane-air mixture at engine-relevant ambient temperatures.

TL;DR: In this paper, the atomic details of the direct oxidation of molten Al nanoparticles (ANPs) with O2, which governs the energy release of Al fuels added in energetic materials, and clarifies the origin of the microexplosion-accelerated oxidation mechanism (MEAOM) mentioned experimentally only.

TL;DR: In this article, the role of differential diffusion characterized by effective Lewis number, Leeff, on the self-similar accelerative propagation and the associated turbulent burning velocity of turbulent expanding flames was clarified and the turbulent flame trajectories of the CH4/H2/air mixtures were measured using a newly developed large-scale, fan-stirred turbulent combustion chamber generating near-isotropic turbulence.

TL;DR: In this paper, a sample-partitioning adaptive reduced chemistry (SPARC) methodology is proposed to mitigate the computational cost of multi-dimensional laminar flames with complex kinetic mechanisms, based on machine learning algorithms which automatically classify the composition space via a priori defined classifiers.

TL;DR: In this article, features of the flame transfer function (FTF) are characterized for turbulent, non-swirled, bluff body stabilized “M” flames for different hydrogen and methane blends including pure hydrogen flames.

TL;DR: In this article, the mass fraction of β-phase polyvinylidene fluoride (PVDF) was increased by 25% to increase the binding energy between Al and PVDF.

TL;DR: In this article, the effects of hydrogen addition on soot formation in methane and ethylene counterflow diffusion flames (CDFs) were studied and kinetically modeled using planar laser-induced incandescence technique.