Project 10: Compressible Flows in Geological Applications: Directed Volcanic Blasts
Adviser(s):
Joanna Austin (Assistant Professor, Aerospace Engineering) and Susan Kieffer (Walgreen Chair and Professor, Geology)
Project description: A rare, but catastrophic, style of volcanic eruption occurs when a dome of hot, viscous, gassy magma on, or within, a volcano collapses. Volatile gases that had been kept under high pressure are suddenly exposed to the lower pressure of the atmosphere, and they expand, often very rapidly. Blasts from these eruptions can hurl gases, magma, rocks and sometimes pieces of glacial ice, across the landscape, causing potentially catastrophic human, social, economic, and ecological consequences. Such a blast occurred on May 18th, 1980 at Mount St. Helens.
Even the best-documented volcanic eruptions are not instrumented to measure key properties of the multiphase flow, such as fluid density, particulate concentration and size distribution as a function of height and time, interior flow velocities (which can differ from observable flow front velocities), and dynamic pressure. An experimental simulation of directed volcanic blasts over an erodible terrain will be carried out in a laboratory-scale experiment.
Student background and expected research activities: This project will involve carrying out shock-tube experiments in the Compressible Fluid Mechanics Lab at the University of Illinois. The interaction of a directed blast with different erodible surfaces will be examined. An existing shock-tube has been modified and a new test section constructed in previous years. The under-expanded jet flow will be visualized with high-speed imaging. The interaction of the jet with solid and erodible surfaces will be examined with a variety of imaging and probe diagnostics. The student will work with a graduate student currently involved in this research. Applicants should have some background in fluid mechanics, preferably having completed their junior year fluids courses. Experimental or other hands-on experience would be helpful, but not necessary.
May 18, 1980 eruption –
USGS photograph by Austin Post.
