TY - JOUR

T1 - Diffusion Combustion of a Round Hydrogen Microjet at Sub- and Supersonic Jet Velocity

AU - Litvinenko, Yu A.

AU - Grek, G. R.

AU - Kozlov, V. V.

AU - Litvinenko, M. V.

AU - Shmakov, A. G.

N1 - Funding Information: This work was supported by the Russian Science Foundation, grant no. 16-19-10330. Publisher Copyright: © 2020, Pleiades Publishing, Ltd. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/9

Y1 - 2020/9

N2 - The experimental research results on diffusion combustion of a round hydrogen microjet flowing from a slit micronozzle at subsonic and supersonic speeds are presented. For the first time, four scenarios of diffusion combustion of a round hydrogen microjet have been identified, including supersonic combustion in the presence of supersonic cells both in air and in hydrogen. It has been found that flame stabilization for a subsonic microjet velocity of hydrogen is associated with the presence of a “bottleneck flame region” leading to the nozzle choking phenomenon, and flame stabilization for a supersonic microjet flow is associated with the presence of supersonic cells. A hysteresis of the diffusion combustion process of a plane microjet of hydrogen is found depending on the method of ignition of the microjet (near or far from the nozzle exit) and the direction of change in the rate of its outflow (growth or decrease).

AB - The experimental research results on diffusion combustion of a round hydrogen microjet flowing from a slit micronozzle at subsonic and supersonic speeds are presented. For the first time, four scenarios of diffusion combustion of a round hydrogen microjet have been identified, including supersonic combustion in the presence of supersonic cells both in air and in hydrogen. It has been found that flame stabilization for a subsonic microjet velocity of hydrogen is associated with the presence of a “bottleneck flame region” leading to the nozzle choking phenomenon, and flame stabilization for a supersonic microjet flow is associated with the presence of supersonic cells. A hysteresis of the diffusion combustion process of a plane microjet of hydrogen is found depending on the method of ignition of the microjet (near or far from the nozzle exit) and the direction of change in the rate of its outflow (growth or decrease).

KW - diffusion combustion

KW - hydrogen round microjet

KW - hysteresis

KW - “bottleneck flame region,” sub- and supersonic combustion

UR - http://www.scopus.com/inward/record.url?scp=85096036562&partnerID=8YFLogxK

U2 - 10.1134/S1028335820090074

DO - 10.1134/S1028335820090074

M3 - Article

AN - SCOPUS:85096036562

VL - 65

SP - 312

EP - 316

JO - Doklady Physics

JF - Doklady Physics

SN - 1028-3358

IS - 9

ER -