Mixing augmentation mechanism induced by the pseudo shock wave in transverse gaseous injection flow fields

Huang, Wei; Li, Minghui; Yan, Li

doi:10.1016/j.ijhydene.2016.04.078

Cited by 39 publications

(4 citation statements)

References 41 publications

(45 reference statements)

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“…Steady state computational data is obtained using compressed real gas Reynolds-averaged Navier-Stokes (RANS) equations, solved by coupled, implicit, second-order upwind solver. The ability of the RANS model to resolve the flow field for similar cases has been proven already in previous studies (20,21) . CFD++ provides the Harten-Laxvan Leer-Contact (HLLC) scheme to solve the cell fluxes.…”

Section: Numerical Schemementioning

confidence: 66%

“…To obtain the data for the performance analysis, the computational domain is divided into 800 sections along the X-axis. Data is extracted along the length of the test section by taking averages over the respective cross sections as defined in (20) . The parameters used for the performance analysis are total pressure loss, mixing efficiency, and flammable plume extent along with fuel jet penetration h/d, where h is the maximum height at which the fuel jet core travels in each cross section and d is the fuel injector diameter.…”

Section: Performance Parameters Definitionmentioning

confidence: 99%

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Effects of pylon geometry on mixing enhancement in a scramjet pylon-cavity flameholder

Oamjee

Sadanandan

2020

Aeronaut. j.

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ABSTRACTNumerical investigation of the effect of pylon geometry within a pylon-cavity aided Supersonic Combustion Ramjet (SCRAMJET) combustor on mixing enhancement, flame-holding capability, fuel jet penetration and total pressure loss are conducted in the current study. RANS equations for compressed real gas are solved by coupled, implicit, second-order upwind solver. A two-equation SST model is used for turbulence modelling. Validation of the computational model is performed with the help of experimental data collected using surface pressure taps, Schlieren flow visualisation and particle image velocimetry (PIV). The study uses four distinct pylon geometry cases, which include the baseline geometry. Sonic injection of hydrogen fuel through a 1mm diameter hole at 2mm downstream of the pylon rear face along the axis of the test section floor is performed for every case. A crossflow of Mach number 2.2 at four bar absolute pressure and standard atmospheric temperature is maintained. A comparative study of mixing efficiency, total pressure loss, fuel jet penetration and fuel plume area fraction for the different cases evaluate the mixing performance. The simulations show that the Pylon 2 case gives a significant improvement in the performance parameters compared to the other geometries. It is observed that mixing efficiency and fuel jet penetration capability of the system are highly dependent on the streamwise vortex within the flameholder.

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Section: Numerical Schemementioning

confidence: 66%

Section: Performance Parameters Definitionmentioning

confidence: 99%

Effects of pylon geometry on mixing enhancement in a scramjet pylon-cavity flameholder

Oamjee

Sadanandan

2020

Aeronaut. j.

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“…With the continuous development of advanced aeroengines for supersonic aircraft, the thermal protection problems caused by high-intensity combustion in the engine and the friction between the engine and the air at high flight speeds urgently need to be solved. , Endothermic hydrocarbons have been proven to be an effective solution to the thermal protection problem of the engine. − Compared with traditional fuels, their endothermic capabilities are limited by their physical heat sinks. Endothermic hydrocarbon fuels will undergo pyrolysis and endothermic reactions at a specific temperature.…”

Section: Introductionmentioning

confidence: 99%

Experimental and Modeling Investigation on the Pyrolysis of n-Decane Initiated by Nitropropane. Part I: 1-Nitropropane

et al. 2023

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Initiators can accelerate the pyrolysis of hydrocarbon fuels, thereby reducing the required reaction temperature in the hypersonic vehicle heat exchanger/reactor. Nitro-alkanes are considered as efficient initiators due to their lower energy barrier of the C–N bond cleavage reaction. To research the mechanism of the initiation effect of nitro-alkanes on the decomposition of hydrocarbon fuel, synchrotron radiation vacuum ultraviolet photoionization-mass spectrometry (SVUV-PIMS) was employed to experimentally study the pyrolysis of n-C10H22, 1-C3H7NO2, and their binary mixtures in a flow tube under pressures of 30 and 760 Torr. The species identified and measured in the experiments included alkanes, alkenes, dialkenes, alkynes, nitrogen oxides, benzene, and free radicals, which revealed the mechanism of n-decane and 1-C3H7NO2 pyrolysis, as well as the interactions of the two fuels. Experiments show that the presence of 1-C3H7NO2 reduces the initial decomposition temperature of n-C10H22, and the increased pressures could achieve a stronger promoting effect on the conversion of n-C10H22. A detailed kinetic model containing 1769 reactions and 278 species was established and validated based on the mole fraction distributions of n-C10H22, major pyrolysis species, and important intermediates measured in pure fuel and initiated pyrolysis. The kinetic model can accurately predict the experimental data, and the mechanism of 1-C3H7NO2-initiated pyrolysis of n-C10H22 is analyzed with the model. The effect of 1-C3H7NO2 on the consumption of n-C10H22 and selectivity of cracked products is highlighted.

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“…With the development of aeroengines for advanced aircrafts with hypersonic or supersonic speed, , endothermic hydrocarbon fuel has been proposed as a good solution for thermal management issues resulting from high intensity combustion in the combustion chamber and high friction with air at high flight speeds. − Endothermic hydrocarbon fuels with a chemical heat sink due to the occurrence of endothermic pyrolysis reactions can take the place of conventional fuels in which the heat-absorbing capacity is limited by a physical heat sink. , Improving the chemical endothermic capacity is essential to increase the heat absorption of endothermic hydrocarbon fuel.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation on Pyrolysis of n-Decane Initiated by Nitropropane under Supercritical Pressure in a Miniature Tube

Jia

Zhou

et al. 2019

Energy Fuels

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Adding an initiator is an effective method of promoting hydrocarbon pyrolysis and improving the heat sink of fuels. Nitropropane was proposed as an initiator with good performance, owing to its lower reaction activation energy for C–N bond cleavage. To study the effects of this initiator on hydrocarbon pyrolysis, a miniature tube reactor that can simulate a real heating procedure in an aeroengine was used to investigate the n-decane pyrolysis with and without nitropropane under experimental supercritical conditions. The results demonstrate that the nitropropane initiator promotes the pyrolysis of fuel as it flows through a tube with a large length–diameter ratio within a certain temperature range. The initial decomposition temperature of n-decane is reduced by approximately 100 K, and the increase in the conversion leads to a higher heat sink for n-decane, which can result in decreases in the fuel and reactor temperatures under the same heating condition and within the effective temperature range. A stronger promoting effect can be achieved by increasing the concentration of the nitropropane initiator. The variation laws for the n-decane pyrolysis reaction rate along the flow reactor are changed by the initiator, the presence of nitropropane greatly accelerates the pyrolysis reaction of fuel at a lower temperature, and the opposite tendency appears as the fuel temperature increases, which is caused by the consumption of the initiator. In addition, the selectivity of methane, propane, and alkenes, especially ethylene, increases because of the propyl radical generated by the C–N dissociation of nitropropane before the initiator is consumed.

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Mixing augmentation mechanism induced by the pseudo shock wave in transverse gaseous injection flow fields

Cited by 39 publications

References 41 publications

Effects of pylon geometry on mixing enhancement in a scramjet pylon-cavity flameholder

Effects of pylon geometry on mixing enhancement in a scramjet pylon-cavity flameholder

Experimental and Modeling Investigation on the Pyrolysis of n-Decane Initiated by Nitropropane. Part I: 1-Nitropropane

Experimental Investigation on Pyrolysis of n-Decane Initiated by Nitropropane under Supercritical Pressure in a Miniature Tube

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