The effect of rotation on stabilization of methane-air premixed Bunsen flames is experimentally investigated. Both the flame blowoff and flashback contours are determined in the fuel mole fraction versus Reynolds number plane (XF-Re) with the rotational Reynolds number Rer as a parameter. It is found that rotation of the gas increases the flame stabilization area As = AB - AF defined as the difference between the flame blowoff AB and flashback AF areas in the (XF-Re) plane. The flame stabilization efficiency is defined as ηs = 1 - AF/AB that approaches unity in either AB → ∞ or AF → 0 limit. The experimental results suggest that rotation decreases the flame stabilization efficiency. However, rotation is found to substantially increase the flame stabilization coefficient defined as βs = As/Ast, where Ast is the stabilization area of the standard nonrotating burner. The parameters ηs and βs may be useful in combustion technology for quantitative evaluation of the stabilization performance of different types of flame holders. In addition, the local hydrodynamics near the center of rotating Bunsen burner is simulated by investigating stabilization of planar laminar premixed flames on rotating porous disks with uniform surface velocity. Physical concepts concerning mechanisms of flame stabilization are discussed in terms of three important parameters namely the translational Reynolds number Re, the rotation Reynolds number Rer, and the fuel mole fraction XF. The results of the experimental findings are shown to be in accordance with prior theoretical investigation.
ASJC Scopus subject areas
- Chemical Engineering(all)
- Fuel Technology
- Energy Engineering and Power Technology
- Physics and Astronomy(all)