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Prikladnaya Mekhanika i Tekhnicheskaya Fizika, 2009, Volume 50, Issue 2, Pages 167–177
(Mi pmtf1729)
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This article is cited in 3 scientific papers (total in 3 papers)
Gas-dynamic signs of explosive eruptions of volcanoes. 2. Model of homogeneous-heterogeneous nucleation. Specific features of destruction of the cavitating magma
V. K. Kedrinskii Lavrent’ev Institute of Hydrodynamics, Siberian Division, Russian Academy of Sciences, Novosibirsk, 630090, Russia
Abstract:
The dynamics of state of the crystallite-containing magma is studied within the framework of the gas-dynamic model of bubble cavitation. The effect of crystallites on flow evolution is considered for two cases: where the crystallites are cavitation nuclei (homogeneous-heterogeneous nucleation model) and where large clusters of crystallites are formed in the magma in the period between eruptions. In the first case, decompression jumps are demonstrated to arise as early as in the wave precursor; the intensity of these jumps turns out to be sufficient to form a series of discrete zones of nucleation ahead of the front of the main decompression wave. Results of experimental modeling of an explosive eruption with ejection of crystallite clusters (magmatic “bombs”) suggest that a cocurrent flow of the cavitating magma with dynamically varying properties (mean density and viscosity) transforms to an independent unsteady flow whose velocity is greater than the magma flow velocity. Experimental results on modeling the flow structure during the eruption show that coalescence of bubbles in the flow leads to the formation of spatial “slugs” consisting of the gas and particles. This process is analyzed within a combined nucleation model including the two-phase Iordansky–Kogarko–van Wijngaarden model and the model of the “frozen” field of mass velocities in the cavitation zone.
Keywords:
magma, dynamics of state, gas-dynamic model, nucleation, decompression wave.
Received: 04.06.2008
Citation:
V. K. Kedrinskii, “Gas-dynamic signs of explosive eruptions of volcanoes. 2. Model of homogeneous-heterogeneous nucleation. Specific features of destruction of the cavitating magma”, Prikl. Mekh. Tekh. Fiz., 50:2 (2009), 167–177; J. Appl. Mech. Tech. Phys., 50:2 (2009), 309–317
Linking options:
https://www.mathnet.ru/eng/pmtf1729 https://www.mathnet.ru/eng/pmtf/v50/i2/p167
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