This study investigates the stabilization behaviors of the counterflow diffusion flame over a porous cylindrical burner in a wind tunnel. The varying parameters are the inflow velocity, the fuel ejection velocity and the fuel ejection area over the burner. The transition processes and the corresponding flame configurations are observed and recorded by a digital video camera. It finds that the characteristics of the flames can be categorized into four regions (I-IV) for the burner with the front half fuel-ejection area, whereas there exist two regions (V and VI) with the full fuel-ejection one. In regions of I, II, and III (low-speed inflow regions), the flames are retained as an envelope flame, whose flame front surrounds the porous cylinder. As the inflow velocity increases to a critical value, the flame front will be broken up from the forward stagnation area and retreated to downstream, transforming into a wake flame directly. On the other hand, in regions of IV and V, envelope, wake, lift-off, and late wake flames appear in order as the inflow velocity increases. In region VI, the envelope flame directly becomes lift-off flame, and no wake flame is observed between them. As the inflow velocity increases further, the wake flame reappears after the lift-off flame. Additionally, the corresponding quantitative analyses and phenomenal explanations are given for a better understanding on the physical mechanisms for the flame structure transitions over a Tsuji burner.
|Number of pages||14|
|Journal||Journal of the Chinese Society of Mechanical Engineers, Transactions of the Chinese Institute of Engineers, Series C/Chung-Kuo Chi Hsueh Kung Ch'eng Hsuebo Pao|
|State||Published - 1 Jun 2006|
- Counterflow flame
- Lift-off flam
- Porous cylinder