高能量密度下汇聚几何界面失稳诱导的转捩和湍流混合机理研究

针对核武器和惯性约束聚变（ICF）等国家重大任务需求，本项目聚焦于高能量密度条件下汇聚几何界面失稳和湍流混合这一影响武器性能和ICF点火的关键科学问题，理论、实验和数值模拟相结合，拟开展如下研究：（1）发展先进激光加载实验技术和高分辨测试诊断技术，在国内建立高能量密度柱几何界面失稳实验能力；（2）基于热力学相容原理发展时空耦合的高效、高精度数值模拟方法，建立适用于汇聚几何界面失稳的数百亿网格规模的直接数值模拟（DNS）能力；（3）研究高能量密度条件下汇聚几何界面失稳中的转捩机制和湍流结构生成、演化机理，确定界面失稳转捩至湍流的判据、参数范围和转捩机制，探索极端条件下湍流混合演化可能存在的新现象、新机制；(4) 发展经激光加载实验和DNS数据综合校验的适用于汇聚几何界面失稳的两方程自由剪切湍流模型。本项目通过提高对界面失稳和湍流混合的科学认识，支撑武器物理和ICF点火设计等国家重大战略任务。

In view of the great national requirement of researches on nuclear weapons and inertial confinement fusion (ICF), this project intends to focus on the key scientific issues of the instability and turbulent mixing of converging geometric interfaces (CGIs) under high energy density (HED) conditions, which significantly affects the performance of the nuclear weapons and ICF ignition. By combining theoretical analysis, experiments and numerical simulations, the following researches will be carried out. (1) By developing the advanced laser-driven experiment and high-resolution test diagnostic technologies, we will establish the capability of performing cylindrical interface instability experiments under HED conditions in China. (2) Based on the thermodynamic-compatible principles, we will develop space-time coupled, high-order numerical methods to establish the massive direct numerical simulation (DNS) capability under tens of billions of grids. (3) We will also recognize the transition, formation and evolution mechanism of turbulent structures in the process of instability of CGIs under HED conditions, determine the conditions, parameter ranges and transition mechanism of the transition to turbulence, and explore the new phenomena and mechanism in such flows. (4) We will finally develop a two-equation free-shear turbulence model, which will be calibrated by laser-driven experiments and comprehensive verification of DNS data. By enhancing the scientific understanding of interfacial instability and turbulent mixing, this projectin will support major national strategic tasks such as weapon engineering and ICF ignition design.