Résumé : A non-modal linear hydrodynamic stability analysis of ablation waves is carried out for the first
time. This analysis is performed for unsteady self-similar solutions in slab symmetry of the
Euler equations with nonlinear heat conduction, using a direct-adjoint method that results from
a Lagrangian-based optimization problem. Such solutions are considered in connection with
inertial confinement fusion (ICF) experiments where the hydrodynamic stability of ablative
flows has been identified as a key issue to the achievement of thermonuclear burn. Inherently
unsteady, these flows are compressible, highly nonuniform with a steep heat front, and bounded
by a material surface and a shock front — features that are possible sources of non-modal
thermo-acoustics effects. Non-modal effects are presently exhibited on a particular ablation wave
solution. This finding raises the question of the existence and consequences of such effects in
configurations of X-ray driven ablation that are more representative of ICF experiments, which
is the object of an ongoing investigation.
https://hal-polytechnique.archives-ouvertes.fr/hal-02615048
Contributor : Grégoire Varillon <>
Submitted on : Friday, May 22, 2020 - 8:56:24 AM Last modification on : Saturday, May 30, 2020 - 3:47:41 AM
Grégoire Varillon, Jean-Marie Clarisse, Arnaud Couairon. Non-modal hydrodynamic stability analysis of ablation flows relative to inertial confinement fusion. Congrès Français de Mécanique, Association française de mécanique, Aug 2019, Brest, France. ⟨hal-02615048⟩