Unsteady OneDimensional Flows of a Vibrationally Excited Gas
Yu. N. Grigoryev^{1}, S. V. Meleshko^{2}, P. Siriwat^{3}
^{1}Institute of Computational Technologies, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090, Russia ^{2}School of Mathematics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand ^{3}School of Science, Mae Fah Luang University, Chiang Rai, 57100, Thailand
Keywords: vibrationally excited gas, onedimensional unsteady equations, admitted Lie algebra, selfsimilar solutions
Abstract
Complete group analysis of the system of onedimensional unsteady equations of the dynamics of a vibrationally excited gas is performed in the case of cylindrical and spherical symmetry. It is shown that the admitted Lie algebra does not contain the scaling generator of independent variables that defines the wellknown selfsimilar solutions of strong shock wave problems for the similar system of the gas dynamics equations of an ideal gas. A modification of the characteristic relaxation time is proposed, which makes it possible to extend the admitted Lie algebra of the system by the generator of simultaneous scaling of independent variables and introduce a class of selfsimilar solutions. Using the problem of a strong linear explosion as an example, it is shown that the solution of the modified system of equations is physically consistent and fairly accurately describes the wellknown effect of the divergence of static and vibrational temperatures behind the wave front.
