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Examples of Gas Motion and Certain Hypotheses on the Mechanism of Stellar Outbursts

Published online by Cambridge University Press:  03 August 2017

L. I. Sedov*
Affiliation:
Academy of Sciences of the U.S.S.R., Moscow, U.S.S.R.

Extract

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In connection with the problem of the explanation of stellar outbursts exact solutions for gas flows with spherical symmetry can be given in the following three cases.

1. Propagation of detonation waves from the interior to the surface of a star, accompanied by an output of nuclear energy on the wave front. Effects of the increase of detonation velocity depending upon the law of density decrease from the center to the outer layer (failure of Chapman-Jourguet's rule) are investigated. As a result of a sufficiently rapid density decrease one obtains a complete dispersion of the detonation products with the formation of a vacuum near the center. Similar solutions are obtained for the spherical problem of the propagation of a rarefaction jump, accompanied by an energy output (a jump of flame front type) through a gas at rest.

2. Perturbed gas motion due to an explosion caused by a sudden large output of energy inside a star. The energy is transferred to the surface together with the shock wave. Exact automodel solutions of the equations for adiabatic time-dependent gas motion, accompanied by the formation of a vacuum when γ=Cp/Cv = 4/3 and without it, are given, gravitation being taken into account. Some solutions for larger values of y are studied.

3. Examples of dynamically unstable equilibrium states disturbed by an explosion followed by the development of a shock wave, propagating through a gas at rest with density gradient. A motion without energy output develops. The energy of the disturbed motion at any time is equal to the initial energy in the equilibrium state.

Type
Part VII: Some General Gas-Dynamical Problems
Copyright
Copyright © American Physical Society 1958 

References

1 Sedov, L. I., Methods of Similarity and Dimensions in Mechanics (Moscow, 1957), 3rd edition 1954, 4th edition 1957.Google Scholar

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6 Kulikovsky, A. G., Doklady Akad. Nauk S.S.S.R. 117, 199 (1957).Google Scholar