Flow and Temperature Characteristics of a 15° Backward-Inclined Jet Flame in Crossflow

• Published in: Energies (Basel) Vol. 12; no. 1; p. 132
• Main Authors: Hsu, Ching Min, Mosiria, Dickson Bwana, Jhan, Wei Chih
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-01-2019
• Subjects: Chemical reactions; CMOS; Cross flow; crossflow; Exposure; Extinguishing; Fluids; jet flame; Jet flow; Light sources; Lithium; Lithium fluoride; Neodymium; Organic chemistry; particle image velocimetry; Photography; Pulsed lasers; recirculation flame; Research methodology; Researchers; Reynolds number; Standard error; Temperature distribution; Temperature profiles; Velocity; Vortices; Yttrium; Taiwan
• ISSN: 1996-1073; 1996-1073
• DOI: 10.3390/en12010132

The flow and flame characteristics of a 15° backward-inclined jet flame in crossflow were investigated in a wind tunnel. The flow structures, flame behaviors, and temperature fields were measured. The jet-to-crossflow momentum flux ratio was less than 7.0. The flow patterns were investigated using photography and Mie-scattering techniques. Meanwhile, the velocity fields were observed using particle image velocimetry techniques, whereas the flame behaviors were studied using photographic techniques. The flame temperatures were probed using a fine-wire R-type thermocouple. Three flame modes were identified: crossflow dominated flames, which were characterized by a blue flame connected to a down-washed yellow recirculation flame; transitional flames identified by a yellow recirculation flame and an elongated yellow tail flame; and detached jet dominated flames denoted by a blue flame base connected to a yellow tail flame. The effect of the flow characteristics on the combustion performance in different flame regimes is presented and discussed. The upwind shear layer of the bent jet exhibited different coherent structures as the jet-to-crossflow momentum flux ratio increased. The transitional flames and detached jet dominated flames presented a double peak temperature distribution in the symmetry plane at x/d = 60. The time-averaged velocity field of the crossflow dominated flames displayed a standing vortex in the wake region, whereas that of the detached jet dominated flames displayed a jet-wake vortex and a wake region source point.