Abstract This paper presents an experimental investigation into the flow rate of natural gas released underwater from a pipe orifice and the associated combustion behavior on the water surface in an aerodynamic channel. A stainless-steel pipeline with a diameter of 25 mm was placed in a water tank of 1 m (height) ×0.5 m (width) ×0.5 m (length). Methane gas was released from a cylinder controlled by a flow meter and pressure gauge. Ten k-type thermocouples, fixed in two directions, were used to measure the temperature profile. The variation parameters of orifice diameter (1 mm, 3 mm, 5 mm), pressure range (0.02 to 0.55 MPa) and gas release depth (0.4 m, 0.6 m, and 0.8 m) were varied to study the flame geometry and temperature profile. A digital CCD camera and an infrared camera are employed to record the visible and temperature distribution, respectively. Results show that flame temperature decreases vertically; an initially high temperature region in the core flame quickly decreases in the plume region. Flame oscillation behavior is due to gas diffusion and flame turbulence. The stability of a burning flame is dependent on an increase in leakage pressure and large orifice diameter; shallow water depths provide greater flame stability. A new correlation is proposed to characterize the flame height to diameter ratio and the dimensionless heat release rate Q*.

中文翻译：

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天然气水下泄漏与水面燃烧火焰的实验研究

摘要 本文介绍了对从管道孔口释放到水下的天然气流速和空气动力通道中水面相关燃烧行为的实验研究。将一根直径为25 mm的不锈钢管道置于1 m（高）×0.5 m（宽）×0.5 m（长）的水箱中。甲烷气体从一个由流量计和压力表控制的钢瓶中释放出来。十个 k 型热电偶，固定在两个方向，用于测量温度分布。改变孔口直径（1 mm、3 mm、5 mm）、压力范围（0.02 至 0.55 MPa）和气体释放深度（0.4 m、0.6 m 和 0.8 m）的变化参数以研究火焰几何形状和温度分布. 采用数码CCD相机和红外相机记录可见光和温度分布，分别。结果表明，火焰温度垂直下降；核心火焰中最初的高温区域在羽状区域中迅速降低。火焰振荡行为是由于气体扩散和火焰湍流。燃烧火焰的稳定性取决于泄漏压力的增加和较大的孔口直径；较浅的水深提供更大的火焰稳定性。提出了一种新的相关性来表征火焰高径比和无量纲放热率 Q*。燃烧火焰的稳定性取决于泄漏压力的增加和较大的孔口直径；较浅的水深提供更大的火焰稳定性。提出了一种新的相关性来表征火焰高径比和无量纲放热率 Q*。燃烧火焰的稳定性取决于泄漏压力的增加和较大的孔口直径；较浅的水深提供更大的火焰稳定性。提出了一种新的相关性来表征火焰高径比和无量纲放热率 Q*。