极小装药爆炸驱动两级重载荷研究

根据瞬时爆轰理论,在极小装填比(C/M)条件下进行了小质量装药驱动大质量载荷运动研究,理论分析了弱约束和强约束装药条件下载荷驱动速度。弱约束装药条件下在格尼方程基础上通过考虑装药壳体径向飞散获得二维炸药驱动载荷运动的计算模型,强约束条件下按照爆轰产物等熵膨胀理论获得大质量载荷驱动速度的计算模型。开展了两种约束条件下爆炸驱动大质量载荷的运动试验研究,弱约束条件下,载荷驱动速度随着装药长径比减小而增大;强约束条件下,载荷驱动速度随着装药量增加而增大,随装药腔体与运动腔体直径比增大而增大。     

HMX炸药爆轰产物物态方程研究

采用自主研制的考虑产物组分间化学反应的类CHEQ程序研究HMX炸药爆轰产物物态方程,给出初始密度为1.90 g·cm^-3的HMX炸药CJ点的爆速和爆压,计算值与实验值符合较好;计算CJ点的爆轰产物组成,并与BKW和LJD的计算结果进行比较分析;同时给出过CJ点的等熵膨胀线上压强、 γ和产物组分随比体积的变化规律,加深对爆轰产物作功能力的认识.     

炸药爆轰的连续介质本构模型和数值计算方法

假定炸药和爆轰产物处于局部热力学平衡状态, 即它们的压力和温度相同, 利用热力学基本关系建立炸药爆轰过程的连续介质本构模型的一般理论框架. 在此框架下, 炸药爆轰本构模型由一组常微分方程构成, 包括炸药和爆轰产物的状态方程、简单混合法则、化学反应速率方程和能量守恒方程, 易于由成熟的计算方法如梯形法等进行求解. 一组广义Maxwell型非线性固体本构形式的微分方程描述了压力和温度随时间的演化速率与应变率和化学反应速率的关系, 借助简单混合物理论, 其中的系数由炸药和爆轰产物的材料参数确定. 未反应的炸药和爆轰产物采用JWL状态方程, 化学反应率方程采用Lee-Tarver点火-燃烧二项式模型, 模拟PBX-9404炸药的一维冲击波起爆过程和爆轰波传播过程. 计算结果表明了本文给出的本构模型和相应计算方法的有效性. 关键词： 炸药爆轰 本构模型 化学反应率方程 数值模拟     

HMX炸药燃烧转爆轰数值模拟

以两相流模型为基础,气相产物状态方程采用基于统计物理的类CHEQ的计算结果,建立了HMX炸药的燃烧转爆轰数学模型。采用CE/SE方法模拟了颗粒度为125μm的HMX炸药的燃烧转爆轰过程,得到了爆轰参数及流场变化规律。模拟了装填密度对HMX炸药燃烧转爆轰的影响,并与实验进行了对比。数值模拟结果表明,在相同的点火条件下,爆轰成长距离在一定范围内随装填密度呈"U"形变化。     

以HMX为基的两种压装高密度炸药的燃烧转爆轰实验研究

 为研究以HMX为基的固体高能炸药的燃烧转爆轰性能,采用同轴电探针和压力传感器测试技术对常用的A、B两种压装高密度高能炸药开展燃烧转爆轰实验,研究装药组分和约束条件对压装高密度炸药燃烧转爆轰性能的影响。实验结果表明：这两种压装高密度炸药难以发生燃烧转爆轰;在强约束条件下（45号钢,内径25.4 mm、外径65 mm、长度600 mm）,A压装炸药（HMX质量分数为95%,密度为1.86 g/cm³）基本实现了燃烧转爆轰,爆轰诱导距离约为545 mm;在相同的实验条件下,A压装炸药比B压装炸药（HMX质量分数为87%,密度为1.84 g/cm³）更易于发生燃烧转爆轰,即A压装炸药的安定性相对较差。     

RDX炸药爆轰产物物态方程

采用基于统计物理的爆轰产物物态方程模型,研究了不同初始密度下RDX炸药爆轰产物性质,发现炸药初始密度小于1.20g/cm3时,炸药爆轰后只有气相产物生成,随着炸药初始密度进一步增大,爆轰后有固相碳析出。炸药初始密度小于1.60g/cm3时,各气相产物按均匀混合处理,计算的爆速、爆压和实验值符合较好。随着炸药初始密度进一步增大,计算的爆速、爆压与实验值出现较大的偏差,经分析发现此处可能出现了超临界流体相分离现象,在物态方程模型中考虑了这种效应后,得到较好的结果。     

低真空条件下炸药强爆轰驱动实验

二级炸药强爆轰驱动超高速飞片的作用基本过程如下：第一级炸药爆轰驱动初级飞片撞击第二级炸药／飞片组合，在次级炸药中形成强爆轰，使其爆轰产物流动区成为较均匀分布的高压区，从而使得强爆轰驱动的次级飞片速度达到中高速或超高速。     

猛炸药RHT-901和钝感炸药IHE-2的爆轰波直角绕射

 采用高速转镜分幅相机和电探针技术研究了猛炸药RHT-901和钝感炸药IHE-2的爆轰波直角绕射图像和不同位置上的爆轰波传播时间。从研究得出，两种炸药都在拐角顶点附近绕射，爆轰波传播时间增长，爆速变小。但是两种炸药绕射爆轰波的状态不一样，钝感炸药IHE-2中爆轰波绕过直角时，在拐角顶点附近约10 mm范围内炸药未完全反应，猛炸药RHT-901中爆轰波绕过直角时未出现类似现象。两者相比，钝感炸药中绕射爆轰波速度变化大，波阵面曲率半径小，而猛炸药的绕射爆轰波速度变化小，波阵面曲率半径大。这说明炸药的爆轰波绕射与炸药的冲击感度、反应区宽度有关。     

多元混合炸药爆轰驱动圆筒膨胀规律的理论确定方法

为快速预估任意配比的多元混合炸药爆轰产物的JWL(Jones-Wilkins-Lee)参数,提出了快速确定多元混合炸药爆轰驱动圆筒膨胀规律的理论方法,即在给定各组分爆轰产物JWL参数的前提下,根据能量守恒定律,采用Gurney模型,确定圆筒试验中多元混合炸药爆轰驱动圆筒膨胀距离随时间变化的曲线。同时,利用能量守恒原理以及经典爆轰理论中通过常γ状态方程得到的爆速、爆压和爆热之间的关系式,提出了确定多元混合炸药爆速和爆压的方法。采用该理论方法,分别计算了多元混合炸药PBXC03和PBXC10爆轰驱动圆筒膨胀规律及爆速和爆压,计算结果与前人的实验结果符合较好,验证了该理论方法的可行性和有效性。     

炸药强爆轰的研究

 对强爆轰波的传播和驱动问题进行了初步的研究,应用有关的理论对这一问题进行了分析,实验上测量了两种炸药中强爆轰的传播或衰减过程,给出了强爆轰驱动飞片的一个算例,与实验测量结果吻合,上述结果在一定程度上揭示了强爆轰的行为。     

Particle confinement and density profile behaviour on HL-1M

In this paper the density profile behaviour and the particle confinement operation regime on HL-1M have been studied under the pellet injection (PI), supersonic molecular beam injection (SMBI), gas puffing (GP) and lower hybrid current drive experimental situations. The relationships between density profile, particle confinement time and edge safe factor have been explored. The density profile, which is measured by six-channel far-infrared ray laser interferometer has been analysed by using the peaking coefficient calculation code. Changes of the outward and inward diffusion velocities before and after the peaking of the central density profile have been calculated using the global particle balance equations. The particle confinement operation regimes have been discussed. The peaking density profile can be easily obtained under the condition of efficient fuelling. In ohmic discharges, confinement time increases as the peaking density profile factor rises, and is saturated at a critical value related to the fuelling efficiency. The particle confinement time of SMBI lies between the values of GP and PI, and its value is about 3-5 times of the energy confinement time.     

HL─1装置等离子体输运与锯齿特性的数值研究

本文利用一维圆柱等离子体输运编码（ＴＲＡＮＰＹ），编制了模拟锯齿振荡的大型编码（ＳＡＷＭＯＤ）。对锯齿振荡的研究，我们选用了两种具有代表性的理论模型：重联模型和湍流模型，后者特别适用于低ｑａ放电的锯齿特性研究。重联模型的锯齿振荡是由于磁力线的完全重联引起的，而湍流模型的锯齿振荡是因为微观湍流或磁力线的随机化而产生的。最后，我们将ＨＬ─１装置的一次典型高密放电的参数代入（ＳＡＷＭＯＤ）编码，运算结果表明，重联模型和湍流模型均能解释实验观测的锯齿现象，理论模拟与实验结果符合较好。     

Spectroscopic Study of Laser-Induced Cu Plasma With and Without the Confinement of a Substrate

Optical emission spectroscopic studies have been carried out on the laser-induced copper plasma generated in the process of laser-driven flyer (with the substrate confinement). The copper plasma in the air (without the substrate confinement) has also been researched in order to know the differences between the plasma with the confinement and that without the confinement. The plasma is assumed to be in local thermodynamic equilibrium. The result shows that, under the same laser fluence, the plasma exists a longer time with the confinement. The time-resolved electron temperature and density with the confinement are higher than those with no confinement. The substrate deposited with Cu foil plays an important role in enhancing the temperature and the density of the plasma. The electron temperature and density with confinement increase with a larger scope as the laser fluence increases than that with no confinement.      

利用低杂波改善约束的实验研究

介绍了在HT-6M托卡马克上,利用双低杂波的组合,成功地实现了准稳态的高约束模式运行. 能量约束时间提高两倍以上,粒子的约束在较高密度下依然改善3倍以上.通过应用波扩散及 电流径向扩散方程计算低杂波电流传播的方法,对一组典型的数据进行数值模拟.计算表明 ,在HT-6M低杂波实验中,由于纵场较低,密度较高,低杂波的能量沉积在离磁轴较远的位 置,使等离子体电流密度分布成为反剪切位形,内部输运垒地形成,大大提高了等离子体的 约束状况.实验数据也给出了反剪切的证据. 关键词： 托卡马克 低杂波 约束改善     

An efficient approximate method for solving the problem of the establishment of chemical equilibrium in the products of explosion of gas mixtures

A method for calculating the changing composition of the explosion products in the case where the chemical equilibrium is absent but the bimolecular reactions are in quasi-equilibrium is developed. At each time step of numerical integration, the change in the total number of molecules in the system is calculated using a single differential equation written based on the selected kinetic mechanism. Then, the mixture composition is calculated under the assumption that the entropy of the mixture reaches its maximum value at a given internal energy, mass density, and molar mass. It is shown that the proposed method can be used to calculate the characteristics of explosive transformation processes after the induction period.     

Radial transport dynamics studies of SMBI with a newly developed TPSMBI code

In tokamak plasma fueling, supersonic molecule beam injection(SMBI) with a higher fueling efficiency and a deeper penetration depth than the traditional gas puffing method has been developed and widely applied to many tokamak devices.It is crucial to study the transport dynamics of SMBI to improve its fueling efficiency, especially in the high confinement regime. A new one-dimensional(1D) code of TPSMBI has also been developed recently based on a six-field SMBI model in cylindrical coordinate. It couples plasma density and heat radial transport equations together with neutral density transport equations for both molecules and atoms and momentum radial transport equations for molecules. The dominant particle collisional interactions between plasmas and neutrals, such as molecule dissociation, atom ionization and charge-exchange effects, are included in the model. The code is verified to be correct with analytical solutions and also benchmarked well with the trans-neut module of BOUT++ code. Time-dependent radial transport dynamics and mean profile evolution are studied during SMBI with the TPSMBI code in both slab and cylindrical coordinates. Along the SMBI path, plasma density increases due to particle fuelling, while plasma temperature decreases due to heat cooling. Being different from slab coordinate, the curvature effect leads to larger front densities of molecule and atom during SMBI in cylindrical coordinate simulation.     

A New Calculation of the In-Medium Quark Condensate at Finite Density andTemperature

The in-medium quark condensate is studied with an equivalent-mass approach in which one does not need to make assumptions on the derivatives of model parameters with respect to the quark current mass. It is shown that the condensate is generally a decreasing function of both the density and
temperature with the decreasing speed depending on the confinement parameter. Specially, at given density, the condensate decreases on increasing temperature. The decreasing speed is comparatively small at lower temperature, and becomes very fast at higher temperature.     

聚-α-甲基苯乙烯热降解产物研究

 降解芯轴技术是制备激光惯性约束聚变靶丸的重要技术之一。采用热分析技术研究了聚-α-甲基苯乙烯（PAMS）热降解温度，采用裂解色谱-质谱联用技术分析了PAMS的热降解产物。研究表明：PAMS降解温度范围为260～320 ℃，在此温度下PAMS降解产物主要是α-甲基苯乙烯单体，另外还有微量四氢呋喃溶剂残留及α-甲基苯乙烯二聚体。因主链上季碳原子的存在，PAMS的热降解过程以端基裂解的解聚反应为主，单体产率超过99%。     

Test-based thermal explosion model for HMX

We present a thermal explosion (cookoff) model for an HMX-based plastic bonded explosive (LX-10). The thermal–chemical–mechanical response of LX-10 is modeled based on the measurements from the scaled thermal explosion experiment (STEX) at the Lawrence Livermore National Laboratory. Confined LX-10 is heated at a rate of 1 °C/h until an explosion is observed. The modeled cookoff problem is simulated by the Arbitrarily Lagrangian–Eulerian hydrocode (ALE3D) that can handle a wide spectrum of time scales that vary from a structural to a high speed shock physics time scale. In addition to a comprehensive model for energetic material, the confinement material namely an AerMet 100 steel is modeled as a Steinberg–Guinan material with a Johnson–Cook failure model with a statistical failure distribution. By using the size distribution data from the fragmentation experiment, the metal fracture and fragmentation due to an explosion are modeled. The explosion temperature is predicted to within 1°. Calculated wall strain provides violence associated with the thermal explosion process and agrees favorably with the measured STEX data.     

微波射频场在微波管中产生爆炸电子发射特性初步分析

 对微波射频场在微波管内引起的场致发射和爆炸电子发射及等离子体的产生进行了分析,推导了等离子体产生强度与微波振幅、材料的电阻率、热传导系数、质量密度和比热容之间的关系,得到了晶须温度分布的表达式,通过数值解析的方式总结出在远大于微波周期的时间尺度上晶须温度提高随时间线性上升。在模型所述材料特性下,温度的上升率达到了3.22×10¹⁰ ℃/s,在100 ns量级就可以使晶须发生气化形成等离子体。