The current research focuses on the analysis of different dynamic effects of an air pocket located at mid-pipe length on transient pressures based on experimental data. Different flow rates and air pocket volumes are analysed. Several features are identified in the pressure-head signal associated with the air pocket: initial pressure drop, higher maximum overpressure peaks, increased pressure wave damping and delay. These features result from the superposition of pressure waves associated with the entrapped air contraction and expansion. Smaller air pockets generate minor reflections, whereas larger air-pockets tend to disperse and artificially attenuate maximum pressures. Video recording images of the air pocket during the transient event allow observation of two types of behaviour: one associated with lower transients, characterized by an air pocket volume variation with a clear air–water interface; and another one associated with more severe transients in which air mixes with water. Finally, there is a critical air pocket volume, independent of the initial flow rate, that leads to the highest overpressures.

目前的研究重点是基于实验数据分析位于管道中段的气穴对瞬态压力的不同动态影响。分析了不同的流速和气穴体积。在与气穴相关的压头信号中确定了几个特征：初始压降、更高的最大超压峰值、增加的压力波阻尼和延迟。这些特征是由与滞留空气收缩和膨胀相关的压力波叠加造成的。较小的气穴产生较小的反射，而较大的气穴倾向于分散并人为地减弱最大压力。瞬态事件期间气穴的视频记录图像允许观察两种类型的行为：一种与较低的瞬态相关，特点是气穴体积变化与清晰的空气 - 水界面; 另一个与空气与水混合的更严重的瞬变有关。最后，与初始流速无关的临界气穴体积会导致最高过压。