The burning and extinction characteristics of a methane diffusion flame in corotating and counterrotating counterflows are experimentally and theoretically investigated. On the basis of the large activation energy asymptotics and the similarity solutions, theoretical predictions are in favorable agreement with the experimental observations on variations of the flame temperature, the flame position and extinction condition with the angular velocity. Results show that by increasing the angular velocity, the flame temperature of a strong diffusion burning is increased to maximum and then decreased; however, the methane concentration at flame extinction is decreased to minimum and thereafter increased without regard to either corotating or counterrotating counterflow. On the flame extinction, the linear envelope of the extinction curve is valid only for the injection velocity larger than 25 cm/sec in rotating counterflows. The extinction profile for smaller injection velocity is curved for both rotating and nonrotating counterflows. Finally, it is found that the absolute minimum fuel concentration on local extinction for diffusion burning cannot be properly identified by the linear extrapolation of the extinction curve.
|Number of pages||8|
|Journal||JSME International Journal, Series 2: Fluids Engineering, Heat Transfer, Power, Combustion, Thermophysical Properties|
|Publication status||Published - 1992 Jan 1|
All Science Journal Classification (ASJC) codes
- Mechanical Engineering
- Physical and Theoretical Chemistry
- Fluid Flow and Transfer Processes