Shakhov-type extension of the relaxation time approximation in relativistic kinetic theory and second-order fluid dynamics

Autor: Victor E. Ambruş, Etele Molnár
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Physics Letters B, Vol 855, Iss , Pp 138795- (2024)
Druh dokumentu: article
ISSN: 0370-2693
DOI: 10.1016/j.physletb.2024.138795
Popis: We present a relativistic Shakhov-type generalization of the Anderson-Witting relaxation time model for the Boltzmann collision integral to modify the ratio of momentum diffusivity to thermal diffusivity. This is achieved by modifying the path on which the single particle distribution function fk approaches local equilibrium f0k by constructing an intermediate Shakhov-type distribution fSk similar to the 14-moment approximation of Israel and Stewart. We illustrate the effectiveness of this model in case of the Bjorken expansion of an ideal gas of massive particles and the damping of longitudinal waves through an ultrarelativistic ideal gas.
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