- Author
- McCaffrey, B. J. | Evans, D. D.
- Title
- Very Large Methane Jet Diffusion Flames.
- Coporate
- National Bureau of Standards, Gaithersburg, MD
- Book or Conf
- Combustion Institute, Symposium (International) on Combustion, 21st. August 3-8, 1986, Combustion Inst., Pittsburgh, PA, Munich, West Germany, 25-32 p., 1986
- Keywords
- diffusion flames
- Abstract
- Methane jet diffusion flames with heat release rates approaching 350 MW in both subsonic and supercritical configurations have been studied regarding lift-off height and flame height, absolute flame stability temperature and radiative characteristics. Lift-off heights are in line with small scale literature results, i.e., Lf/Ue = 3.3 ms, albeit with considerable scatter. Although the ratio of flame height to actual orifice diameter exceeded 400 in the supercritical regime, the correlated data are suggestive of relatively smaller flame heights than obtained at laboratory scale, in the Becker and Liang nomenclature psi never fell below 0.33 as xiL -> 0. Flames from orifices up to 38 mmD could be blown off with sufficient gas pressure. For D = 51 mm the flame could not be blown off for stagnation pressures as high as 2300 kPa. The data point at 38 mm allows a more accurate extrapolation, in the manner of Kalghatgi, leading to a predicted critical orifice size of 48 mm for absolute flame stability for CH4. Failure to ignite gas from a 1 mm diameter aperture in a reservoir at 12,000 kPa is consistent with the shape of the upper portion of the locus of the derived stability curve.