This paper presents experimental results on disintegration of initially unatomized extinguishing liquid arrays in the free fall from a variable height. In laboratory conditions, the discharge height varied in the range of 0.5–3 m, and in field tests it was 3–15 m. The initial volume of unatomized liquid varied in the range of 0.05–1 l. The following compositions were considered: water without impurities, bentonite suspension, foam agent emulsion, bischofite and flame retardant solutions. When processing the research results, four stages of transformation of liquid arrays, leading to the formation of an aerosol, were determined. Data obtained in the experiments served to establish the dependences of the surface area covered by the discharged liquid. Using such dependences, the transformation characteristics of non-sprayed liquid arrays with volumes of up to 5000 l (maximum for helicopters) and 20000 l (maximum for airplanes) at discharge heights of up to 100 m were calculated. General approximation expressions for water, suspension, solution and emulsion were obtained to describe these dependences, taking into account the influence of the properties of liquids (viscosity, density and surface tension) through the Ohnesorge number. These expressions allow predicting the minimum discharge heights of non-sprayed arrays with different component composition and volume, sufficient for the formation of an aerosol cloud with virtually unchanged dimensions (the forest coverage area, respectively) and dispersion.

中文翻译：

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自由落体时最初未雾化的灭火液体阵列的转变

本文介绍了从可变高度自由落体中最初未雾化的灭火液体阵列崩解的实验结果。在实验室条件下，排放高度在0.5–3 m范围内变化，在现场测试中为3–15 m。未雾化液体的初始体积在0.05-1 l的范围内变化。考虑以下组成：无杂质的水，膨润土悬浮液，泡沫剂乳液，重水铁矿和阻燃剂溶液。在处理研究结果时，确定了导致阵列形成气溶胶的四个阶段的液体阵列转换。在实验中获得的数据有助于确定排放液体覆盖的表面积的依赖性。利用这种依赖性，计算了最大喷射高度为100 m时最大容积为5000 l（直升机最大）和20000 l（飞机最大）的非喷雾液体阵列的转换特性。考虑到液体的性能（粘度，密度和表面张力）通过Ohnesorge数的影响，获得了水，悬浮液，溶液和乳液的一般近似表达式以描述这些依赖性。这些表达式可以预测具有不同成分组成和体积的未喷雾阵列的最小排放高度，足以形成尺寸（实际上分别为森林覆盖面积）和分散度不变的气溶胶云。