Stabilization of Double Flames Interacting with the Intersecting Flow on a V-Shaped Burner

Abstract

Two impinging premixed flames interacting with an intersecting flow stabilized on a novel V-shaped burner were investigated through particle-image velocimetry (PIV) with high temporal resolution (1280 × 1024 pixels at 1040 Hz) and color-image capture at 6000 fps. The results showed that stable operation over a wide range was achieved, relative to a flat-type burner. The mechanism of flame stabilization was approached through a double-flame structure strongly interacting with the intersecting flow from a zone of high temperature (about 1900 K) and vorticity (600 s−1) to enhance the preheated effect on the unburned reactant. The heat release of the non-premixed flame was uniquely entrained into the premixed flame zone by the recirculation. The flame shape altered significantly from conical to concave at ratio U j/S L = 2.3 and was classified as detached flame, merging flame, and contact flame; the period of evolution of the merging flame was 6.6 ms. The region of intense turbulence overlapping with the premixed flame was consistent with the high temperature due to the interaction between flame and recirculation, especially near the stoichiometric ratio. Compared to a traditional flat-type burner, the V-shaped burner achieves excellent performance, indicating that this novel concept is favorable for the burner design in industrial and domestic applications.