Opening of a system of cracks—on the mechanism of the cyclic lateral eruption of the St. Helens volcano in 1980

• Published in: Journal of applied mechanics and technical physics Vol. 57; no. 4; pp. 577 - 587
• Main Authors: Kedrinskii, V. K., Davydov, M. N., Pilnik, A. A., Chernov, A. A.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.07.2016; Springer Nature B.V
• Subjects: Applications of Mathematics; Boundary conditions; Channels; Classical and Continuum Physics; Classical Mechanics; Cracks; Dynamical systems; Fluid flow; Fluid- and Aerodynamics; Hydrodynamics; Mathematical analysis; Mathematical Modeling and Industrial Mathematics; Mathematical models; Mechanical Engineering; Melts; Physics; Physics and Astronomy; multiphase mathematical model; viscosity; magma melt; boundary layer; slot volcanic eruption; decompression wave; cavitation
• ISSN: 0021-8944; 1573-8620
• DOI: 10.1134/S0021894416040015

The dynamic behavior of a magma melt filling a slot channel (crack) in a closed explosive hydrodynamic structure is considered. The explosive hydrodynamic structure includes the volcano focal point with a connected vertical channel (conduit) closed by a slug and a system of internal cracks (dikes) near the dome, as well as a crater open into the atmosphere. A two-dimensional model of a slot eruption is constructed with the use of the Iordanskii–Kogarko–van Wijngaarden mathematical model of two-phase media and the kinetics that describes the basic physical processes in a heavy magma saturated by the gas behind the decompression wave front. A numerical scheme is developed for analyzing the influence of the boundary conditions on the conduit walls and scale factors on the melt flow structure, the role of viscosity in static modes, and dynamic formulations with allowance for diffusion processes and increasing (by several orders of magnitude) viscosity. Results of the numerical analysis of the initial stage of cavitation process evolution are discussed.