Numerical Simulation of Wall Treatment Effects on the Micro-Scale Combustion

Authors: R. Kamali, A. R. Binesh, S. Hossainpour

Abstract:

To understand working features of a micro combustor, a computer code has been developed to study combustion of hydrogen–air mixture in a series of chambers with same shape aspect ratio but various dimensions from millimeter to micrometer level. The prepared algorithm and the computer code are capable of modeling mixture effects in different fluid flows including chemical reactions, viscous and mass diffusion effects. The effect of various heat transfer conditions at chamber wall, e.g. adiabatic wall, with heat loss and heat conduction within the wall, on the combustion is analyzed. These thermal conditions have strong effects on the combustion especially when the chamber dimension goes smaller and the ratio of surface area to volume becomes larger. Both factors, such as larger heat loss through the chamber wall and smaller chamber dimension size, may lead to the thermal quenching of micro-scale combustion. Through such systematic numerical analysis, a proper operation space for the micro-combustor is suggested, which may be used as the guideline for microcombustor design. In addition, the results reported in this paper illustrate that the numerical simulation can be one of the most powerful and beneficial tools for the micro-combustor design, optimization and performance analysis.

Keywords: Numerical simulation, Micro-combustion, MEMS, CFD, Chemical reaction.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1078719

References:

[1] Carlos Fernandez-Pello, A., 2002. Micro-power generation using combustion: issues and approaches. Twenty-Ninth International Symposium on Combustion, Sapporo, Japan, the Combustion Institute
[2] Ono, S., Wakuri, Y., 1977. An experimental study on the quenching of flame by narrow cylindrical passage. Bulletin of JSME 20 (147)
[3] Glassman, I., 1996. Combustion. Academic Press, California.
[4] Lee, D.H., Kwon, S., 2002. Heat transfer and quenching analysis of combustion in a micro combustion vessel. Journal of Micromechanics and Micro engineering 12, 670-676.
[5] Norton, D.G., Vlachos, D.G., 2003. Combustion characteristics and flame stability at the micro-scale: a CFD study of premixed methane/air mixtures. Chemical Engineering Science 58, 4871-4882.
[6] Norton, D.G., Vlachos, D.G., 2004. A CFD study for propane/air microflame stability. Combust. Flame 138, 97-107.
[7] Choi , K.H., Na, H.B., Lee, D.H., Kwon, S., 2004. Numerical simulation of flame propagation near extinction condition in a micro-combustor. Micro-scale Thermophysical Engineering 8, 71-89.
[8] Spadaccini, C.M., Mehra, A., Lee, J., Zhang, X., Lukachko, S.,Waitz, A.I., 2003. High power density silicon combustion system for micro gas turbine engines. Journal of Engineering for Gas Turbines and Power 125, 709-719.
[9] Ronney, P.D., 2003. Analysis of non-adiabatic heat-recirculating combustors. Combust. Flame 135 (4), 421.