Maximal Kinematical Invariance Group of Fluid Dynamics and Applications

The maximal kinematical invariance group of the Euler equations of fluid dynamics for the standard polytropic exponent is larger than the Galilei group. Specifically, the inversion transformation <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline...

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Bibliographic Details
Main Authors: V. V. Sreedhar, Amitabh Virmani
Format: Article
Language:English
Published: MDPI AG 2022-06-01
Series:Universe
Subjects:
Online Access:https://www.mdpi.com/2218-1997/8/6/319
Description
Summary:The maximal kinematical invariance group of the Euler equations of fluid dynamics for the standard polytropic exponent is larger than the Galilei group. Specifically, the inversion transformation <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>(</mo><mo>Σ</mo><mo>:</mo><mi>t</mi><mo>→</mo><mo>−</mo><mn>1</mn><mo>/</mo><mi>t</mi><mo>,</mo><mspace width="0.166667em"></mspace><mover accent="true"><mi>x</mi><mo>→</mo></mover><mo>→</mo><mover accent="true"><mi>x</mi><mo>→</mo></mover><mo>/</mo><mi>t</mi><mo>)</mo></mrow></semantics></math></inline-formula> leaves the Euler equation’s invariant. This duality has been used to explain the striking similarities observed in simulations of the supernova explosions and laboratory implosions induced in plasma by intense lasers. The inversion symmetry extends to discontinuous fluid flows as well. In this contribution, we provide a concise review of these ideas and discuss some applications. We also explicitly work out the implosion dual of the Sedov’s explosion solution.
ISSN:2218-1997