Flame Acceleration in Narrow Channels: Applications for Micropropulsion in Low-Gravity Environments

Vadim N. Gamezo; Elaine S. Oran

doi:10.2514/1.16446

Flame Acceleration in Narrow Channels: Applications for Micropropulsion in Low-Gravity Environments

AIAA Journal ◽

10.2514/1.16446 ◽

2006 ◽

Vol 44 (2) ◽

pp. 329-336 ◽

Cited By ~ 29

Author(s):

Vadim N. Gamezo ◽

Elaine S. Oran

Keyword(s):

Low Gravity ◽

Narrow Channels ◽

Flame Acceleration

Download Full-text

Quasi-steady stages in the process of premixed flame acceleration in narrow channels

Physics of Fluids ◽

10.1063/1.4819885 ◽

2013 ◽

Vol 25 (9) ◽

pp. 096101 ◽

Cited By ~ 11

Author(s):

D. M. Valiev ◽

V. Bychkov ◽

V. Akkerman ◽

L.-E. Eriksson ◽

C. K. Law

Keyword(s):

Premixed Flame ◽

Narrow Channels ◽

Flame Acceleration

Download Full-text

Flame acceleration and deflagration-to-detonation transition in narrow channels with thin obstacles

Modern Physics Letters B ◽

10.1142/s0217984918503542 ◽

2018 ◽

Vol 32 (29) ◽

pp. 1850354 ◽

Cited By ~ 1

Author(s):

Jin Huang ◽

Xiangyu Gao ◽

Cheng Wang

Keyword(s):

Turbulent Flame ◽

Narrow Channels ◽

Flame Acceleration ◽

Deflagration To Detonation Transition ◽

Smooth Channel ◽

Detonation Transition ◽

Run Up ◽

Thin Obstacle ◽

Strong Confinement ◽

Small Spacing

The entire process of deflagration-to-detonation transition (DDT) in narrow channels with thin obstacle configurations is studied through high-resolution simulations. The results show that the confinement and disturbance of obstacles promote considerably the flame acceleration and DDT. There exist two modes of DDT associating with obstacle spacing S. For small spacing S, the flame acceleration depends on strong confinement and jet flow between obstacles; eventually DDT occurs due to early burning amplified by shocks in front of the flame. However, for large spacing S, the flame acceleration is mainly attributed to turbulence; DDT results from the interaction of reflection shock with turbulent flame. It is found that the run-up distance of DDT in the obstructed channels shortens significantly, as compared with that in the smooth channel.

Download Full-text

Computational Study of Premixed Flame Propagation in Micro-Channels with Nonslip Walls: Effect of Wall Temperature

Fluids ◽

10.3390/fluids6010036 ◽

2021 ◽

Vol 6 (1) ◽

pp. 36

Author(s):

Orlando J. Ugarte ◽

V’yacheslav Akkerman

Keyword(s):

Flame Propagation ◽

Computational Study ◽

Reacting Flow ◽

Narrow Channels ◽

Flow Equations ◽

Flame Acceleration ◽

Flame Dynamics ◽

Micro Channels ◽

Fuel Mixtures ◽

The Impact

This investigation evaluates the propagation of premixed flames in narrow channels with isothermal walls. The study is based on the numerical solution of the set of fully-compressible, reacting flow equations that includes viscosity, diffusion, thermal conduction and Arrhenius chemical kinetics. Specifically, channels and pipes with one extreme open and one extreme closed are considered such that a flame is sparked at the closed extreme and propagates towards the open one. The isothermal channel walls are kept at multiple constant temperatures in the range from Tw=300 K to 1200 K. The impact of these isothermal walls on the flame dynamics is studied for multiple radii of the channel (R) and for various thermal expansion ratios (Θ), which approximate the thermal behavior of different fuel mixtures in the system. The flame dynamics in isothermal channels is also compared to that with adiabatic walls, which were previously found to produce exponential flame acceleration at the initial stage of the burning process. The results show that the heat losses at the walls prevent strong acceleration and lead to much slower flame propagation in isothermal channels as compared to adiabatic ones. Four distinctive regimes of premixed burning in isothermal channels have been identified in the Θ−Tw−R space: (i) flame extinction; (ii) linear flame acceleration; (iii) steady or near-steady flame propagation; and (iv) flame oscillations. The physical processes in each of these regimes are discussed, and the corresponding regime diagrams are presented.

Download Full-text