Regime diagrams and characteristics of flame patterns in radial microchannels with temperature gradients

Comprehensive regime diagrams of flame pattern formation in radial microchannels with temperature gradients were drawn based on experimental findings. A premixed methane–air mixture was introduced at the center of microchannels formed by two parallel circular quartz plates that were heated with an external porous burner to create a positive temperature gradient condition in the direction of flow. Combustion behavior in those microchannels at channel widths of 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mm were experimentally investigated. Regime diagrams of various stable and unstable flame patterns were obtained, confirming that the flame pattern is a strong function of mixture equivalence ratio, inlet mixture velocity, and channel width. Furthermore, some combustion characteristics, such as the rotating frequency of the single pelton-like flame and the triple flame, the radius of the stable circular flame front, and comparison between the major combustion products of the single and double pelton-like flames, were also investigated.

[1]  F. Spellman.  Combustion Theory , 2020 .

[2]  D. Spalding,et al.  INTRODUCTION TO COMBUSTION , 1979 .

[3]  Williams,et al.  Rotating spiral edge flames in von karman swirling flows , 2000, Physical review letters.

[4]  P. Clavin,et al.  Linear Stability Analysis of Nonadiabatic Flames: Diffusional-Thermal Model , 1979 .

[5]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[6]  Andrew G. Glen,et al.  APPL , 2001 .

[7]  H. Pearlman.  Excitability in high-Lewis number premixed gas combustion , 1997 .

[8]  Wei Liu,et al.  Experimental study on flame pattern formation and combustion completeness in a radial microchannel , 2007 .

[9]  Fingering Instability in Combustion , 1997, cond-mat/9707333.

[10]  Sergey Minaev,et al.  Nonlinear dynamics of flame in a narrow channel with a temperature gradient , 2007 .

[11]  R. Masel,et al.  Flame dynamics and structure within sub‐millimeter combustors , 2007 .

[12]  Meng-Jing Wu,et al.  An improved micro-combustor design for micro gas turbine engine and numerical analysis , 2005 .

[13]  Jinsong Hua,et al.  Numerical simulation of the combustion of hydrogen–air mixture in micro-scaled chambers Part II: CFD analysis for a micro-combustor , 2005 .

[14]  Robbins,et al.  Ratcheting motion of concentric rings in cellular flames. , 1996, Physical review letters.

[15]  F. Weinberg,et al.  A burner for mixtures of very low heat content , 1974, Nature.

[16]  G. Sivashinsky,et al.  Instabilities, Pattern Formation, and Turbulence in Flames , 1983 .

[17]  P. Ronney.  Analysis of non-adiabatic heat-recirculating combustors , 2003 .

[18]  Shigenao Maruyama,et al.  Flame stabilization and emission of small Swiss-roll combustors as heaters , 2005 .

[19]  A. Bayliss,et al.  Structure and dynamics of kink and cellular flames stabilized on a rotating burner , 1996 .

[20]  D. G. Norton,et al.  Combustion characteristics and flame stability at the microscale: a CFD study of premixed methane/air mixtures , 2003 .

[21]  Ian A. Waitz,et al.  High Power Density Silicon Combustion Systems for Micro Gas Turbine Engines , 2003 .

[22]  S. Minaev,et al.  Characteristics of Microscale Combustion in a Narrow Heated Channel , 2004 .