Steady flame streets in a non-premixed microburner

Mackay, Kyle K.; Johnson, Harley T.; Freund, Jonathan B.

doi:10.1016/j.combustflame.2019.05.018

Cited by 9 publications

(6 citation statements)

References 54 publications

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“…Quenching is more significant in these reduced-scale burners due to the higher channel surface-to-volume ratio. In simulations of CH 4 -O 2 and H 2 -O 2 combustion, flame extinction and flame street formation were observed [26], matching experimental observations [23,27]. H 2 -O 2 flames were sustained in reduced-scale burners, albeit with low combustion completeness (20%-60%).…”

Section: Geometrysupporting

confidence: 80%

“…The target solutions  U target at the inlets is the initial condition. The burner behavior was confirmed to be insensitive to the choice of target for the outlet sponge [26].…”

Section: Boundary Conditionsmentioning

confidence: 90%

“…Flames in the mixing layer divert flow from the center of the channel due to thermal expansion and consume the mixed fuel and oxygen, reducing the mixedness. For the reduced-size burners, the diffusion mixing layer spans a larger fraction of the channel in smaller burners and the reactants are well-mixed shortly after the streams join [26]. Because the mixing layer occupies a larger fraction of the channel, the mixedness increases faster and achieves higher values in the smaller burners.…”

Section: Baseline Case Without Fe-dbd Arraysmentioning

confidence: 99%

“…Coupling previous field-emission plasma [19] and microcombustor simulation models [26], we develop a simulation model for the combined system. The corresponding model without plasma has sufficient fidelity to reproduce flame instabilities and burner performance in corresponding experiments [26]. The combined model is used to examine the effects of arrays of FE-DBD actuators inside the burner channel.…”

Section: Introductionmentioning

confidence: 99%

“…The details of the microburner model and the FE-DBD model and its integration into the combustion simulation are discussed in section 2. Burner performance without plasma actuation is discussed in section 3.2, with more results available elsewhere [26]. Corresponding simulations with FE-DBD arrays in two candidate configurations, selected to emphasize different effects of the actuation are discussed in section 3.3.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Field-emission plasma enhancement of H₂–O₂ micro-combustion

Mackay

Johnson²,

Freund³

2020

Plasma Sources Sci. Technol.

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A detailed three-dimensional computational model is developed to assess the potential of micronscale field emission dielectric barrier discharge (FE-DBD) plasma actuators in non-premixed microburners with channel heights in the range of L z =0.25-0.75 mm. Results for H 2 -O 2 combustion with Reynolds number Re=100 are studied for different configurations of plasma actuator arrays. Without plasma actuation, results agree with corresponding experiments, although in this case the burner typically suffers from incomplete combustion due to thermal quenching, radical quenching, and slow diffusive mixing. For the range of conditions simulated, plasma actuation increases combustion completeness from 25%-70% to 40%-80% by enhancing mixing, generating radicals, and Joule heating. Ionic wind resulting from the FE-DBD plasma disrupts the otherwise simple laminar flow in the burner, accelerating the growth of a mixing layer and enhancing heat transfer to channel walls. The larger, lower temperature flames reduce thermal gradients (and thereby thermal stresses) in the walls. Radical generation due to electron-impact dissociation extends the reaction zone in the diffusion flame and increases combustion completeness. In all cases, the additional heat release with plasma actuation (100-190 W) is significantly larger than the power needed to sustain the plasma (0.1 W), suggesting that plasma actuation may provide a significant advantage in energy generation using realistic portable micro-combustion devices.

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Section: Geometrysupporting

confidence: 80%

“…The target solutions  U target at the inlets is the initial condition. The burner behavior was confirmed to be insensitive to the choice of target for the outlet sponge [26].…”

Section: Boundary Conditionsmentioning

confidence: 90%

Section: Baseline Case Without Fe-dbd Arraysmentioning

confidence: 99%