内爆加载下果冻内外界面不稳定性数值计算

在界面不稳定性实研究中，一个主要的难点是如何分隔不同流体介质并形成初始扰动，其中比较新颖的方法是利用乙炔和氧气的混合气体爆轰来驱动果冻内爆，由于果冻有足够强度抵抗重力引起的变形，无须任何膜来控制界面，同时果冻和爆轰产物都具有良好的透明性，易于观察界面扰动情况，廖海东等也做过类似实验，并获得了测试图像。     

银纳米粒子簇的设计、 制备和表面增强拉曼光谱

通过匹配激光光斑直径与胶体微球的尺寸, 设计制备了银纳米粒子的表面增强拉曼散射(SERS)基底, 并将其用于研究单个银纳米粒子簇的表面增强拉曼光谱. 在制备纳米粒子的过程中, 考察了等离子体刻蚀时间与银沉积厚度对“单”银纳米粒子结构与形貌的影响. 将吡啶、 巯基苯和罗丹明R6G作为SERS探针分子, 研究了其SERS效应, 通过荧光共振能量转移(FRET)机理, 实现了染料分子在单银纳米粒子簇上的SERS效应. SERS光谱测试与相关计算结果表明, 单个银纳米粒子簇的拉曼增强因子能够达到约10⁶.     

Experimental and numerical investigation of inclined air/SF6 interface instability under shock wave

The shock tube experiments of inclined air/SF6 interface instability under the shock wave with the Mach numbers 1.23 and 1.41 are conducted. The numerical simulation is done with the parallel algorithm and the multi-viscous-fluid and turbulence (MVFT) code of the large-eddy simulation (LES). The developing process of the interface accelerated by the shock wave is reproduced by the simulations. The complex wave structures, e.g., the propagation, refraction, and reflection of the shock wave, are clearly revealed in the flows. The simulated evolving images of the interface are consistent with the experimental ones. The simulated width of the turbulent mixing zone (TMZ) and the displacements of the bubble and the spike also agree well with the experimental data. Also, the reliability and effectiveness of the MVFT in simulating the problem of interface instability are validated. The more energies are injected into the TMZ when the shock wave has a larger Mach number. Therefore, the perturbed interface develops faster.     

点起爆炸药驱动圆板击靶波形的数值模拟研究

用自行研制的二维流体动力学程序TDY2D对点起爆驱动圆板运动的3个模型进行数值模拟计算,得到的飞片击靶波形与实验波形均符合较好,具有较高的计算精度,验证了该程序的准确性和有效性。通过对爆轰驱动飞片运动过程数值模拟结果的分析,得到了装置参数对飞片击靶波形影响规律的初步认识。