Abstract This work focuses on studying the oscillating length scale of gas pipeline leakage flame restricted by parallel sidewalls with various separation distances. A series of experiments are conducted with 3, 6 and 10 mm nozzles and propane is used as fuel. Results show that reduction of the sidewall separation distance hinders the air entrainment, and provokes significant enlargement of the oscillation amplitude. Besides, the oscillating length scale of propane jet fire is also found to increase with the fuel flow rate. Finally, a new physical model, based on the scaling analysis of the fuel flow field and previous work, is proposed to characterize the variation of oscillating length for the restricted propane jet fire. The results obtained in this work and in previous studies, correlate with a better agreement using the present model than a previous suggested model. This work is not only a significant supplement to the flame oscillation instability physics from previous results for the flame restricted by parallel sidewalls, but also can provide some scientific basis to the design and management on the gas fuel energy storage and transportation systems in the cities to reduce the possible fire thread to the surrounding buildings.

中文翻译：

---

平行侧壁约束燃气管道泄漏火焰振荡长度尺度的试验研究

摘要 本文重点研究了不同间距平行侧壁限制的燃气管道泄漏火焰的振荡长度尺度。使用 3、6 和 10 毫米喷嘴进行了一系列实验，并使用丙烷作为燃料。结果表明，侧壁间隔距离的减小阻碍了空气夹带，并引起了振荡幅度的显着增大。此外，还发现丙烷喷射火的振荡长度尺度随着燃料流量的增加而增加。最后，基于燃料流场的比例分析和先前的工作，提出了一种新的物理模型来表征受限丙烷喷射火的振荡长度的变化。在这项工作和以前的研究中获得的结果，与使用当前模型比以前建议的模型更好的一致性相关。该工作不仅是对前人平行侧壁约束火焰的火焰振荡不稳定物理结果的重要补充，也可为城市气体燃料能源储运系统的设计和管理提供一定的科学依据。减少对周围建筑物的可能火线。