HR: 0800h
AN: V31E-0713    [Abstracts]
TI: Preliminary SAGE Simulations of Volcanic Jets Into a Stratified Atmosphere
AU: * Peterson, A H
EM: audreyp@lanl.gov
AF: University of Wisconsin - Milwaukee, P.O. Box 413, 2200 E. Kenwood, Milwaukee, WI 53201, United States
AU: * Peterson, A H
EM: audreyp@lanl.gov
AF: Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, United States
AU: Wohletz, K H
EM: wohletz@lanl.gov
AF: Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, United States
AU: Ogden, D E
EM: dogden@es.ucsc.edu
AF: University of California - Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, United States
AU: Gisler, G R
EM: galen.gisler@fys.uio.no
AF: University of Oslo, PO Box 1081 Blindern, Oslo, NO-0317, Norway
AU: Glatzmaier, G A
EM: glatz@es.ucsc.edu
AF: University of California - Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, United States
AB: The SAGE (SAIC Adaptive Grid Eulerian) code employs adaptive mesh refinement in solving Eulerian equations of complex fluid flow desirable for simulation of volcanic eruptions. The goal of modeling volcanic eruptions is to better develop a code's predictive capabilities in order to understand the dynamics that govern the overall behavior of real eruption columns. To achieve this goal, we focus on the dynamics of underexpended jets, one of the fundamental physical processes important to explosive eruptions. Previous simulations of laboratory jets modeled in cylindrical coordinates were benchmarked with simulations in CFDLib (Los Alamos National Laboratory), which solves the full Navier-Stokes equations (includes viscous stress tensor), and showed close agreement, indicating that adaptive mesh refinement used in SAGE may offset the need for explicit calculation of viscous dissipation.We compare gas density contours of these previous simulations with the same initial conditions in cylindrical and Cartesian geometries to laboratory experiments to determine both the validity of the model and the robustness of the code. The SAGE results in both geometries are within several percent of the experiments for position and density of the incident (intercepting) and reflected shocks, slip lines, shear layers, and Mach disk. To expand our study into a volcanic regime, we simulate large-scale jets in a stratified atmosphere to establish the code's ability to model a sustained jet into a stable atmosphere.
DE: 8409 Atmospheric effects (0370)
DE: 8414 Eruption mechanisms and flow emplacement
DE: 8428 Explosive volcanism
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2007 Fall Meeting