横向风作用下喷口间距对射流扩散火焰特征的影响研究

Study on influence of nozzle spacing on characteristics of jet diffusion flame under cross-wind

为研究横向风作用下喷口间距对射流扩散火焰特征的影响,以双喷口火焰为研究对象,利用CCD摄像机拍摄火焰几何形态,研究横向风条件下喷口间距对火焰形态演化、火焰长度和火焰吹熄极限的影响。研究结果表明:喷口间距较小时,2束火焰因空气夹带竞争和压差作用,彼此相互倾斜融合,火焰融合概率随喷口间距增加而逐渐降低,火焰临界融合间距随横向风的增加先增大后减小;由于火焰的空气夹带和热反馈处于较高水平,2束火焰被少量拉伸,火焰长度先增加后减小;喷口间距较小时,火焰吹熄极限显著增加。

To study the influence of nozzle spacing on the flame combustion characteristics under the condition of cross-wind,taking the dual-nozzle jet fire as the research object,a CCD camera was used to record the flame geometry,and the effect of nozzle spacing on the flame geometry evolution,flame length,and blow-out limit was analyzed under the condition of cross wind.The results show that when the nozzle spacing was smaller,the two flames would incline and merge with each other due to air entrainment competition and pressure difference,and the flame merging probability gradually decreased with the increase of the nozzle spacing.The critical flame merge spacing increased first and then decreased with the increases of cross-wind speed.Due to the high level of air entrainment and thermal feedback,the length of the two flames was slightly stretched,the flame length would first increase and then decrease.When the nozzle spacing was smaller,the blow-out limit of flame increased significantly.