Experimental investigation on flame morphology and wall-attached flame temperature of jet flame under the coupled effect of nozzle angle and nozzle-wall spacing

• Published in: Fuel (Guildford) Vol. 367; p. 131463
• Main Authors: Lu, Gaoming, Cong, Haiyong, Yuan, Ziqi, Shao, Zhuyu, Ye, Lili, Bi, Yubo, Bi, Mingshu, Yu, Binshan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2024
• Subjects: Flame morphology; Impingement jet; Jet fire; Nozzle angle; Wall-attached flame; Impingement jet; Flame morphology; Jet fire; Wall-attached flame; Nozzle angle
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2024.131463

•The effect of nozzle-wall spacing and nozzle angle on restricted jet was investigated.•The morphology of jet flame and the temperature of wall-attached flame were analyzed.•Dimensionless formulas with trace length and vertical height of flame were proposed.•A dimensionless relation to predict temperature of wall-attached flame was proposed. Jet flames caused by fuel leaks in engineering often occur in complex environments. A total of 140 experiments were conducted to investigate the coupling effect of nozzle angle and nozzle-wall distance on the jet flame characteristics. The results indicate that for upward-tilted jet flame (0° ≤ θ ≤ 90°), the flame trace length has an overall decreasing trend with increasing nozzle angle; when the nozzle is further rotated to a downward slope (θ = 120°), the effect of the nozzle angle on the flame trace length is not consistent as the heat release rate (HRR) increases. In addition, the growth rate of the flame trace length and the flame vertical length are relatively low compared to the growth rate of HRR. Moreover, it was found that the wall-attached flame temperature had a similar trend of decay along the wall upward for different HRRs; and the maximum wall-attached flame temperature showed an overall decreasing trend as the nozzle-wall spacing increased. Furthermore, new physical models were developed to describe the flame trace length, flame vertical length and temperature rise of wall-attached flame. This work may contribute positive significance to the study of the mechanism of impingement jet flames and the search for preventive solutions.