SGER: Exploring Vulcanian Explosions and Sedimentation Patterns Leading to Pyroclastic Density Currents Using Scaled Laboratory Experiments and Particle Image Velocimetry (PIV):

这项用于探索性研究的小额赠款旨在表征和量化颗粒大小以及源动量和浮力通量对由高度不稳定、短持续时间的震源产生的喷流、羽流和火山碎屑密度流的整体行为的影响(订单10 S)。作为这项研究的一部分，PI将进行可行性实验，使用粒子图像测速仪(PIV)记录射流、羽流和PDC前沿速度作为时间和空间的函数。该项目的长期目标是记录和了解颗粒浓度和沉降率的空间变化以及源的不稳定性如何与整个喷流、羽流和PDC的发展有关。作为这一探索期的一部分，他们将首先测试和演示测量这些参数的有效和适当的方法。如果成功，这种方法将是全面评估火山喷发动力学的核心。这项研究将支持PI和英国布里斯托尔大学的J·C·菲利普斯之间的国际合作努力，并将允许转让实验火山流体动力学领域的技术。拟议的工作将实施旨在研究颗粒流动的实验和数据采集方法，并有可能应用于火山学应用以外的许多其他环境和环境。速度和浓度测量的高速视频分析以及粒子图像测速(PIV)等技术将使该实验室对更广泛的亚利桑那州立大学地球和空间科学界有用，包括对火星上沉积物运输感兴趣的行星科学家。

This Small Grant for Exploratory research seeks to characterize and quantify the effects of particle size and source momentum and buoyancy fluxes on the overall behavior of jets, plumes and pyroclastic density currents (PDC) generated by highly-unsteady, short duration sources (order 10 s). As part of this study, the PI will be undergoing feasibility experiments that use particle image velocimetry (PIV) that record jet, plume and PDC front velocities as functions of time and space. The long-term goals of this project are to document and understand how spatial variations of particle concentration and settling rate, in conjunction with source unsteadiness, relate to overall jet, plume and PDC development. As part of this exploratory period, they will first test and demonstrate efficient and appropriate means of measuring these parameters. If successful, this approach will be central to making a full assessment of Vulcanian eruption dynamics.This research will support an international collaborative effort between the PI and J. C. Phillips from the University of Bristol, in the UK, and will allow a transfer of technology in the field of experimental volcanological fluid dynamics. The proposed work will implement experimental and data-acquisition methods intended for study of particle-laden flows with potential application to many other settings and environments beyond this volcanological application. Techniques such as high-speed video analysis for velocity and concentration measurements as well as Particle Image Velocimetry (PIV) will make the lab useful to the broader Arizona State University Earth and Space Sciences community, including planetary scientists interested in sediment transport on Mars.