Kovásznay modes in stability of self-similar ablation flows of ICFV. Lombard, S. Gauthier, J.-M. Clarisse and C. Boudesocque-Dubois
CEA, DIF - F-91297 Arpajon Cedex, France, EU
received 9 July 2008; accepted in final form 3 September 2008; published October 2008
published online 26 September 2008
The history of the linear perturbations in a “laser imprinting” configuration in inertial confinement fusion is described. The time-dependent mean flow is provided by a self-similar solution of gas dynamics equations with nonlinear heat conduction for semi-infinite slabs of perfect gases. The analysis is conducted with the Kovásznay modes, namely the vorticity, acoustic and entropy modes. Exact propagation equations for these three basic modes are derived. Both the similarity solutions and their linear perturbations are numerically computed with an adaptive multidomain Chebyshev method. In particular, the dynamics of the shock wave is detailed. Compressibility effects and possible implications to inertial confinement fusion experiments are emphasized.
52.57.Fg - Implosion symmetry and hydrodynamic instability (Rayleigh-Taylor, Richtmyer-Meshkov, imprint, etc.).
47.20.-k - Flow instabilities.
52.35.Py - Macroinstabilities (hydromagnetic, e.g., kink, fire-hose, mirror, ballooning, tearing, trapped-particle, flute, Rayleigh-Taylor, etc.).
© EPLA 2008