Combustion characteristics and flame stability at the microscale: a CFD study of premixed methane/air mixtures
TL;DR: In this article, a two-dimensional elliptic, computational fluid dynamics (CFD) model of a micro-burner is solved to study the effects of microburner dimensions, conductivity and thickness of wall materials, external heat losses, and operating conditions on combustion characteristics and flame stability.
About: This article is published in Chemical Engineering Science.The article was published on 2003-11-01. It has received 398 citations till now. The article focuses on the topics: Premixed flame & Micro-combustion.
Citations
More filters
TL;DR: In this article, a review of the development of micro-power generators by focusing more on the advance in fundamental understanding of microscale combustion is presented, and the conventional concepts of combustion limits such as flammability limit, quenching diameter, and flame extinction and heat recirculation are revisited.
621 citations
01 Jan 2005
TL;DR: In this paper, a cylindrical quartz tube with an inner diameter of 2mm was used as a model channel, and the downstream part of the tube was heated by an external heat source, and hence the temperature gradient in the axial direction was formed in the tube.
Abstract: Characteristics of premixed combustion in a heated channel with an inner diameter smaller than the conventional quenching distance of the employed mixture were investigated experimentally, analytically, and numerically. A cylindrical quartz tube with an inner diameter of 2 mm was used as a model channel. The downstream part of the tube was heated by an external heat source, and hence the temperature gradient in the axial direction was formed in the middle of the tube. Flat and stationary conventional premixed flames were stabilized at a point in this temperature gradient. In addition to these flames, various other flames that exhibit dynamic behaviors such as cyclic oscillatory motions, and repetitive ignition and extinction were also observed experimentally. These flames with large amplitude oscillatory motion might be utilized as a heat source with high speed temporal temperature variations in microsystems for future application. Another stable flame region in extremely low speed criteria at a mixture velocity of 2–3 cm/s was also experimentally confirmed. This flame was inferred to be an example of mild combustion, and it might also be used as a mild heat source for microdevices. The overall stability criteria of these flame regimes were analytically examined, and the detailed structure of each flame on the stable solution branches was numerically examined by employing 1D computation with detailed chemistry. The two results qualitatively agreed with each other and clarified the mechanism of the present various flames and their dynamic characteristics.
438 citations
01 Jan 2011
TL;DR: A review of research and development on micro and mesoscale combustion is presented in this article, with an emphasis on fundamental understandings achieved in the field during the last decade, due to its small scale nature, increasing effects of flame-wall interaction and molecular diffusion.
Abstract: A review of research and development on micro and mesoscale combustion is presented, with an emphasis on fundamental understandings achieved in the field during the last decade. Due to its small scale nature, increasing effects of flame–wall interaction and molecular diffusion are the characteristic features of micro and mesoscale combustion. After brief review of device developments, overview of fundamentals in micro and mesoscale combustion as well as possible future directions is presented.
361 citations
TL;DR: In this paper, a review of micro-scale combustion and micro-thermophotovoltaic power generators is presented, and a brief review is made to other micro power generators.
348 citations
TL;DR: A review of microcombustion research can be found in this article, where the authors present technological drivers, applications, devices, and fabrication protocols of microburners, as well as a review of homogeneous, catalytic, homogeneous-heterogeneous and heat recirculating micro-burners.
324 citations
References
More filters
Book•
11 Sep 1985
TL;DR: This paper introduced the physical effects underlying heat and mass transfer phenomena and developed methodologies for solving a variety of real-world problems, such as energy minimization, mass transfer, and energy maximization.
Abstract: This undergraduate-level engineering text introduces the physical effects underlying heat and mass transfer phenomena and develops methodologies for solving a variety of real-world problems.
13,209 citations
TL;DR: In this paper, simplified reaction mechanisms for the oxidation of hydrocarbon fuels have been examined using a numerical laminar flame model, and a simple procedure to determine the best values for the reaction rate parameters is demonstrated.
Abstract: Simplified reaction mechanisms for the oxidation of hydrocarbon fuels have been examined using a numerical laminar flame model. The types of mechanisms studied include one and two global reaction steps as well as quasi-global mechanisms. Reaction rate parameters were varied in order to provide the best agreement between computed and experimentally observed flame speeds in selected mixtures of fuel and air. The influences of the various reaction rate parameters on the laminar flame properties have been identified, and a simple procedure to determine the best values for the reaction rate parameters is demonstrated. Fuels studied include n-paraffins from methane to n-decane, some methyl-substituted n-paraffins, acetylene, and representative olefin, alcohol and aromatic hydrocarbons. Results show that the often-employed choice of simultaneous first order fuel and oxidizer dependence for global rate expressions cannot yield the correct dependence of flame speed on equivalence ratio or pressure and can...
2,062 citations
Book•
01 Jan 1961
TL;DR: The second edition of this book has been in short supply for some time and the authors have decided in favor of a reprint of the book rather than an extensive revision at this time.
Abstract: For some time copies of the second edition of this book have been in short supply. In order to meet, the demand for additional copies the authors have decided in favor of a reprint of the book rather than an extensive revision at this time. The justification for this lies in the character of the book. It was conceived as an exposition of basic concepts of gaseous combustion phenomena. Since the publication of the second edition in 1961 the literature on the subject has grown in volume very greatly. However, virtually no new concepts in gaseous combustion have evolved. For this reason we feel that the book, in its present form, continues to serve well the purpose for which it was intended, namely, to provide a systematic presentation of the fundamentals of combustion for scientists and engineers. In addition, we feel that the present edition has not yet outlived its usefulness as a source of data. Furthermore, the utility of certain concepts is only now beginning to be appreciated. This applies in particular to the concept of flame stretch which permits a unified approach to seemingly widely different sets of phenomena, including ignition, flame extinction, stabilization, quenching, flammability limits, and maximum heat release rates.
1,857 citations
Book•
10 Oct 1996
TL;DR: A survey of laser diagnostics can be found in this paper, where the authors present a survey of the field of laser diagnostic tools and their application in various fields, including: 1. Background Physics 3. Experimental Considerations 4. Application Considerations 5. Spontaneous Raman and Rayleigh Scattering 6. Coherent Anti-Stokes Raman Spectroscopy (CARS) 7. Laser-Induced Fluorescence (LIF) 8.
Abstract: 1. Survey of Laser Diagnostics 2. Background Physics 3. Experimental Considerations 4. Application Considerations 5. Spontaneous Raman and Rayleigh Scattering 6. Coherent Anti-Stokes Raman Spectroscopy (CARS) 7. Laser-Induced Fluorescence (LIF) 8. Coherent Methods for Minor Species 9. Field Techniques
1,736 citations
TL;DR: In this article, the types of dynamic behavior possible for a single first order reaction carried out in a stirred tank reaction are classified according to values of the parameters and plots in parameter space used to define the various possibilites.
655 citations