English

A buoyancy-drag model with a time-varying drag coefficient for evaluating bubble front penetration depth

Fluid Dynamics 2025-01-03 v2

Abstract

To evaluate and control bubble front penetration depth hB{{h}_{B}} induced by ablative Rayleigh-Taylor instability (ARTI) from a weakly nonlinear phase to a self-similar phase, we first propose an improved buoyancy-drag (BD) model with a time-varying drag coefficient. The coefficient incorporates the influence of multiple physical mechanisms, including non-steady ablation, preheating, and other mechanisms during this phase. The model is validated through simulations under various conditions, demonstrating improved accuracy compared to the classical BD model and the self-similar growth. Furthermore, the model suggests controlling hB{{h}_{B}} by suppressing the "most dangerous mode", which is influenced by initial perturbations and ablative acceleration history, thus offering novel insights for target manufacturing and pulse optimization near the ignition threshold.

Keywords

Cite

@article{arxiv.2411.12392,
  title  = {A buoyancy-drag model with a time-varying drag coefficient for evaluating bubble front penetration depth},
  author = {Dongxue Liu and Tao Tao and Jun Li and Qing Jia and Rui Yan and Jian Zheng},
  journal= {arXiv preprint arXiv:2411.12392},
  year   = {2025}
}
R2 v1 2026-06-28T20:04:49.637Z