Jet spreading and Jet inclination induced through complex vent geometry

This dataset provides data from 36 rapid decompression experiments performed in the Fragmentation Lab at Ludwig-Maximilians-Universität München (LMU, Munich, Germany) supporting the publication Schmid, M, Kueppers U, Cigala V, Sesterhenn J and Dingwell DB (202x) “Release characteristics of overpressurised gas from complex vents: implications for volcanic hazards”. The experiments were aimed to constrain the influence of complex vent geometry on the instantaneous gas expansion in a shock-tube setup, mimicking impulsive volcanic explosions. They were performed at the following experimental conditions: 1) six vent geometries (conduit geometry always cylindrical), composed by 2 sets of inner geometry (cylindrical and 15° diverging) with inclined exit planes of 5, 15 or 30° slant angle, 2) constant temperature (25°C), 3) four starting overpressure scenarios (5, 8, 15, 25 MPa), and 4) two reservoir volumes (127.4 cm3, 31.9 cm3), achieved via variable conduit length, with Argon being used for the pressurization. During the experiments the setup is incrementally pressurized. When the desired experimental pressure in the reservoir is reached, rapid decompression is triggered (Kueppers et al., 2006; Cigala et al., 2017), producing a starting jet of expanding gas. Expansion-induced cooling leads to condensation of the Argon jet, allowing for optical analysis of gas expansion dynamics using highspeed videos. Gas dynamics (jet spreading and jet inclination) were analysed and correlated to experimental variables.

本数据集源自德国慕尼黑路德维希-马克西米利安大学（Ludwig-Maximilians-Universität München, LMU）碎裂实验室开展的36次快速减压实验，用于支撑Schmid M、Kueppers U、Cigala V、Sesterhenn J与Dingwell DB于202x年发表的题为“复杂喷口中超压气体的释放特征：对火山灾害的启示”的研究成果。本系列实验旨在限定复杂喷口几何形态对激波管装置中瞬时气体膨胀的影响，以此模拟突发性火山爆炸。实验设置如下：1）6种喷口几何构型（导管几何形态始终为圆柱形），由2组内流几何构型（圆柱形与15°扩张型）搭配5°、15°或30°倾斜角的出口平面组合而成；2）恒定实验温度（25℃）；3）4种初始超压工况（5、8、15、25 MPa）；4）2种储气室容积（127.4 cm³与31.9 cm³），通过调整导管长度实现，实验加压介质为氩气。实验过程中，装置将逐步增压。当储气室达到预设实验压力后，触发快速减压操作（Kueppers等，2006；Cigala等，2017），生成膨胀气体起始射流。膨胀诱导的冷却效应会使氩气射流发生凝结，借此可通过高速摄像对气体膨胀动力学过程开展光学分析。研究人员对气体动力学特征（射流扩散与射流倾角）进行了分析，并将其与实验变量建立关联。