Fire hazards in outdoor environmental conditions cause huge damage to process safety in fuel transportation and pipeline leakage. Few literatures are reported about the combustion behaviors and instability characteristics of dual jet flames under cross wind, which are important to risk assessment and manufacturing design. In this work, a series of propane fire source with nozzle diameters of 3 mm, 4 mm and 5 mm are designed for different nozzle separation distances under cross wind. Results showed the tilt angle of rear jet flame was smaller than front jet flame due to the vitiated effective wind towards the rear jet flame by the blockage of the front jet flame. Furthermore, it’s found that the blow-out cross wind velocity of the rear jet flame is smaller than that of the corresponding single jet flame. The combustion of the front jet flame will restrict the rear jet flame to a certain extent. Finally, dimensional analysis and correlations are established, where the blow-out cross wind velocity of rear jet flame as well as that of the single jet flame can be well represented by Froude number. These new observations and correlation are helpful for further understanding combustion behaviors of dual tandem jet flames under cross wind.

室外环境条件下的火灾危害对燃料运输和管道泄漏的过程安全造成巨大破坏。关于侧风下双射流火焰的燃烧行为和失稳特性的文献报道很少，这对风险评估和制造设计具有重要意义。在这项工作中，针对侧风下不同的喷嘴间距设计了一系列喷嘴直径为3 mm、4 mm和5 mm的丙烷火源。结果表明，由于前部喷射火焰的阻塞，导致后部喷射火焰的有效风被破坏，后部喷射火焰的倾角小于前部喷射火焰。此外，发现后喷焰的吹出横风速小于相应的单喷焰的吹出横风速。前部喷射火焰的燃烧会在一定程度上限制后部喷射火焰。最后，建立了量纲分析和相关性，其中后喷射火焰的吹出横风速以及单喷射火焰的吹出横风速都可以用弗劳德数很好地表示。这些新的观察和相关性有助于进一步了解双串联喷射火焰在侧风下的燃烧行为。