RT Journal Article
T1 Stability of expanding accretion shocks for an arbitrary equation of state
A1 Huete Ruiz de Lira, César
A1 Velikovich, Alexander L.
A1 Martínez Ruiz, Daniel
A1 Calvo Rivera, Andrés
AB We present a theoretical stability analysis for an expanding accretion shock that doesnot involve a rarefaction wave behind it. The dispersion equation that determines theeigenvalues of the problem and the explicit formulae for the corresponding eigenfunctionprofiles are presented for an arbitrary equation of state and finite-strength shocks.For spherically and cylindrically expanding steady shock waves, we demonstrate thepossibility of instability in a literal sense, a power-law growth of shock-front perturbationswith time, in the range of hc < h < 1 + 2M2, where h is the D’yakov-Kontorovichparameter, hc is its critical value corresponding to the onset of the instability and M2is the downstream Mach number. Shock divergence is a stabilizing factor and, therefore,instability is found for high angular mode numbers. As the parameter h increases from hc to 1 + 2M2, the instability power index grows from zero to infinity. This result contrastswith the classic theory applicable to planar isolated shocks, which predicts spontaneousacoustic emission associated with constant-amplitude oscillations of the perturbed shock in the range hc < h < 1 + 2M2. Examples are given for three different equations of state: ideal gas, van der Waals gas and three-terms constitutive equation for simple metals.
PB Cambridge University Press
SN 0022-1120
SN 1469-7645 (Online)
YR 2021
FD 2021-09-29
LK https://hdl.handle.net/10016/36255
UL https://hdl.handle.net/10016/36255
LA eng
NO C.H. work is produced with the support of a 2019 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation and project PID2019-108592RB-C41 (MICINN/FEDER, UE). A.L.V. work was supported by the National Nuclear Security Administration of the U.S. Department of Energy. D.M-R work was supported by project PID2019-108592RA-C43 (MICINN/FEDER, UE).
DS e-Archivo
RD 1 sept. 2024