爆磁压缩技术综述

介绍了把炸药的化学能转换成电磁能的爆磁压缩技术，其中包括了爆磁压缩发生器的组成、运行原理和大量实验。结果表明：爆磁压缩发生器可在mm^3体积内建立1．99GA／m(25Moe)的强磁场；在nH电感性负载中产生超过250-266MA的脉冲大电流；几kg质量的爆磁压缩发生器能在5μH负载两端产生超过50kV的脉冲电压，经过爆炸丝、间隙闭合开关组成的功率调节组件后。可得到高于500kV的脉冲高电压。     

多级柱面炸药内爆磁通量压缩技术研究

柱面内爆磁通量压缩发生器是利用炸药内爆压缩其内部磁通量至轴线附近小体积内从而实现超高磁场,传统的单级装置因受到金属套筒内爆失稳等影响性能指标受限。开展了多级内爆磁压缩技术研究,突破多项关键技术,包括研制特殊结构的密绕螺线管、脉冲功率源及大电流放电开关等,具备在直径135 mm套筒空间内实现20 T以上初始磁场产生能力,并建立了动态磁光测量系统。利用磁流体力学编码SSS-MHD开展多级装置设计,计算显示,设计的多级装置能够将约42%的初始磁通量压缩至轴线附近直径7 mm的空间内。最终研制成功多级内爆磁压缩装置CJ-150,在亚立方厘米以上空间实现轴向峰值磁场强度906 T,数据不确定度5.35%。10余发动态考核实验显示,CJ-150装置工作稳定,能够满足物理实验需要。利用经实验验证的磁流体模型计算显示,CJ-150具备1 000 T以上超强磁场产生能力,能够对大尺寸样品实现500 GPa以上的准等熵加载。     

爆磁压缩发生器可采用的小型便携式初级能源

介绍了几种爆磁压缩发生器可采用的小型便携式初级能源。     

螺旋型爆磁压缩装置的磁通损耗

首先根据在螺旋型爆磁压缩装置实验中获得的微分，积分电流波形，对引起磁通损耗的各种因素进行了细致的分析，得出装置的磁通损耗与装置某些几何参数的关系及其在微分，积分电流波形上的反映；然后从ＭＦＣＧ电路方程及Ｍｉｎｔｓｅｖ磁通损耗系数模型出发，用实验测得的微分，积分电流数据，对每一测量点处的装置初级，次级磁通损耗系数ａ１，ａ２进行了计算。     

铁电体—磁通压缩发生器爆炸电源的电路分析

根据铁电体爆电换能器和磁通压缩发生器的爆电基本原理的分析，给出了该系统输出电流的解析解，估算了几种分流电阻情况下的输出电流和铁电体的电场曲线，并对结果进行了讨论。     

第四次国际百万高斯磁场产生及有关论题学术会议简迅

百万高斯会议是关于强磁场,尤其是以炸药为能源的爆炸磁压缩装置和爆炸电流发生器的系列性专业国际学术会议本次会议于86年7月14日至17日在美国新墨西哥州圣塔菲市召开,共有十一个国家243人参加,交流论文近110篇,大多数来自美国和苏联。我国有三人与会,宣读了西南流体物理研究所关于小型爆炸电流发生器的研究论文。会后组织参观了美国洛斯阿拉莫斯(LANL)圣地亚(SNL)及空军武器实验室(AFWL)等单位。     

磁驱动等熵压缩和高速飞片的实验技术（续3）

5磁驱动等熵压缩和高速飞片的冲击大电流技术与实验研究进展5.1冲击大电流发生器在一定负载上产生数兆安培以至几百兆安培的冲击大电流,是发展脉冲功率技术的主要目的之一。永久性冲击大电流发生器的主要技术途径是通过电容或电感式中间贮能、与负载匹配的快响应传输线或特殊的     

内爆磁压缩准等熵加载过程分析与实验验证

利用磁流体力学程序SSS-MHD模拟了炸药柱面内爆磁通量压缩发生器CJ-100装置的加载过程,讨论了各项装置参数的影响,结果表明装置可达到的峰值磁场值与初始磁场值成反比关系。设计了铁/铜夹层结构的样品靶,在该型装置上开展纯铁的准等熵加载实验。利用光子多普勒测速探头测量到6.43 km/s的样品靶自由面速度,在DT4铁中获得206 GPa的准等熵加载压力。铁材料的压力-比容曲线与理论等熵线基本重合,表明内爆磁压缩加载过程具有较高的等熵程度。     

磁驱动单侧飞片实验的数值模拟

磁驱动单侧飞片实验的数值模拟通常可不考虑厚的阴极的运动状态和厚度方向上烧蚀宽度的影响,采用单侧计算模型进行模拟。为了理解磁驱动单侧飞片实验可采用单侧计算模型的原因,为磁驱动单侧飞片实验的单侧计算建模提供理论依据,建立了磁驱动单侧飞片实验的双侧计算模型,并对PTS-061、PTS-064磁驱动单侧飞片实验进行了模拟分析。在PTS-061、PTS-064实验中,飞片的电流加载面的位移随着时间的增加持续增大;厚的阴极的电流加载面的位移不随时间的增加持续增大,在磁驱动实验中后期基本保持不变。PTS-061实验结束时,飞片的电流加载面的位移为4.9 mm,阴极电流加载面的位移仅为1.7 mm。PTS-064实验结束时,飞片的电流加载面的位移为4.1 mm,阴极电流加载面的位移仅为0.9 mm。磁驱动单侧飞片实验能采用单侧计算模型模拟的原因,不是阴极板面保持位置不动,而是阴极电流加载面的位移不随时间持续增加;在磁驱动实验后期,飞片电流加载面位移对边界磁场的影响远大于阴极电流加载面的位移对边界磁场的影响。     

磁流体压缩管道热电磁流动特性研究

利用磁流体五波模型对低磁雷诺数下压缩管道中磁流体流动进行数值模拟。该模型由带有电磁作用强制项的Navier-Stokes方程组与电势Poisson方程组成,数值格式分别采用严格保证熵条件的熵条件格式和中心差分格式。数值模拟对不同磁作用数下的不同几何外形管道进行数值模拟研究,结果表明在磁流体压缩管道中,由于发生器模式提取...     

Method of designing explosive-driven magnetic field generators

A method of designing explosive-driven magnetic field generators that allows us to establish a dependence between the parameters of the generator circuit, in which the greatest energy release occurs under a time-invariant resistive load, is described. The problem of switching two-dimensional generators to a load whose resistance linearly increases with temperature is analytically solved as an example. The theoretical possibility of designing a generator in which the power released under the resistive load R(t) varies in a specified way with time is demonstrated. Types of current pulse, power, and energy released in the load are studied in the case of different generator circuit parameters.Translated from Zhurnal Prikladnoi Mekhaniki Tekhnicheskoi Fiziki, No. 1, pp. 120–127, January–February, 1976.The author to wxpress his appreciation to E. I. Bichenkov for useful remarks.     

Energy loss and storage in RC-transmission lines

The distribution of energy supplied by a step-voltage generator to a semi-infinite transmission line with uniform series resistance and shunt capacitance is investigated; and explicit (simple integral) representations for both line and generator losses as well as the line storage during an arbitrary time interval are given. A relatively greater loss due to internal resistance of the generator obtains in the initial phase of excitation while that due to resistance of the line predominates in the long run. A larger proportion of energy is stored in the line at the outset and, ultimately, the output of the generator is equally divided between line loss and storage in its internal capacitance.     

Energy transfer from an inductive storage by means of an explosive current disconnect

Energy transfer from an inductive storage is considered for two types of systems: a disconnect with an intrinsic parasitic inductance for an inductive load and a purely resistive disconnect for a resistive load. Solutions are obtained for the voltage, power, and energy transferred to the load. The dependence of the efficiency of the device on its parameters is established.     

Energy transfer from an inductive storage to an inductive load by means of an explosive current disconnect

A study is made of switching of current from an inductive storage by electrical explosion of a wire shunting an inductance in conformity with a model based on surface vaporization waves. It is established that the nature of the process is determined by certain generalized dimensionless parameters of the system. The modes of most efficient transfer of energy to the load are determined.     

带附加质量块的压电圆板能量采集器振动分析

基于圆板的压电能量采集技术在取代化学电池为低功耗电子器件提供能源方面具有巨大的潜能. 本文通过理论建模和数值仿真研究了考虑附加质量接触面积的压电圆板能量采集器的采集性能. 首先, 基于基尔霍夫薄板理论, 用广义哈密顿原理推导了带附加质量块的压电圆板能量采集器的机电耦合方程, 并用伽辽金法对方程近似离散, 通过离散方程得到电压、功率输出和最优负载阻抗的闭合解. 用有限元仿真对所提出的理论模型进行了验证, 结果表明该理论模型可以成功地预测压电圆板能量采集器输出电压和功率. 最后, 基于闭合解探讨了负载阻抗、附加质量块、压电圆板的内外半径等相关参数对压电圆板能量采集器固有频率、输出电压和功率的影响. 结果表明, 当质量块与复合板的接触半径足够小(本文中接触半径小于板半径的1/14)时, 质量块与复合圆板的接触面积可以忽略; 相较于无孔的压电片, 内径位于2.5 ~ 4 mm范围内的压电片可以提高能量采集器的采集性能; 附加质量、压电片外径和负载阻抗的合理选择既可以降低压电圆板的固有频率, 还可以提高其采集性能.      

Velocity statistics along the stagnation line of an axi- symmetric stagnating turbulent flow

 Velocity statistics along the stagnation line of an axi-symmetric wall stagnating turbulent flow are studied experimentally. A low turbulence, uniform air flow from a nozzle type air supply with an exit diameter of 50 mm stagnates at a wall located 50 mm downstream. A flow velocity is set to 3 m/s, 10 mm downstream from the exit of the air supply. Instantaneous values of streamwise and radial velocities are measured by laser-Doppler velocimetry. The turbulence level in the air flow is changed by use of turbulence generator. When the turbulence generator is not installed in the air supply, the mean velocity profile in the streamwise direction fits well with that of a laminar viscous flow with the rms value of velocity fluctuations low near the wall. With the turbulence generator installed, a significant turbulence structure appears near the wall. When the wall is approached, the rms value of velocity fluctuations in the streamwise direction decreases monotonically while the profile of the rms value in the radial direction reaches a maximum near the wall. The increase in the rms value of velocity fluctuations in the radial direction near the wall is attributed to the bi-modal histogram of the fluctuating velocity in the radial direction. Near the wall, the instantaneous stagnation streamline fluctuates and the probability of the mean location of the stagnation point reaches a maximum not at the stagnation line but on a circle around the stagnation line, resulting in the bi-modal histogram. Turbulence statistics, the rms value of velocity fluctuation and the turbulent kinetic energy, can be normalized successfully by similarity parameters based on the strain rate and the reference turbulent kinetic energy introduced by Champion and Libby. Received: 7 April 1995/Accepted: 27 September 1996     

多点导通爆炸逻辑网络闭合开关研制

应用爆炸逻辑网络知识,依据金属射流击穿绝缘薄膜导通放电原理,研制了一种多点导通爆炸逻辑网络闭合开关。在小型脉冲功率发生器上的短路实验及同步性测量结果表明,该开关电感小于5nH,能够承受80kV以上的高电压和兆安级以上的大电流,同步性为55ns,其形状为平板状,便于与平行板状传输线连接。并与单点导通的雷管爆炸闭合开关作了比较,结果表明,多点导通爆炸逻辑网络闭合开关的电感低于单点导通的雷管爆炸闭合开关。上述结果进一步说明,多点导通爆炸逻辑网络闭合开关具有低电感、耐高电压大电流以及便于与平行板传输线连接的特点,在要求回路电感非常小、使用单开关的脉冲功率发生器中具有非常好的应用前景。     

Modeling and preliminary analysis of piezoelectric energy harvester based on cylindrical tube conveying fluctuating fluid

In this contribution, a novel type of piezoelectric tubular energy harvester based on fluctuating fluid pressure is investigated. Analytic model of the proposed energy harvester is built under the assumption of axisymmetric radial vibration. Exact solution of the piezoelectric vibrating tube is obtained with its output performances formulated. A series of numerical simulations are conducted to investigate the influences of geometrical parameters, input mechanical load parameters and output electrical load parameters upon the output performances of the proposed piezoelectric tubular energy harvester. The model and simulation results indicate the potential of the proposed piezoelectric tubular energy harvester. It is expected that the energy harvester be useful in powering wireless sensor network for the health monitoring of hydraulic systems, where fluid conveying pipe vibration is omnipresent.     

COUPLED ANALYSIS FOR THE HARVESTING STRUCTURE AND THE MODULATING CIRCUIT IN A PIEZOELECTRIC BIMORPH ENERGY HARVESTER

The authors analyze a piezoelectric energy harvester as an electro-mechanically coupled system. The energy harvester consists of a piezoelectric bimorph with a concentrated mass attached at one end, called the harvesting structure, an electric circuit for energy storage, and a rectifier that converts the AC output of the harvesting structure into a DC input for the storage circuit. The piezoelectric bimorph is assumed to be driven into flexural vibration by an ambient acoustic source to convert the mechanical energies into electric energies. The analysis indicates that the performance of this harvester, measured by the power density, is characterized by three important non-dimensional parameters, i.e., the non-dimensional inductance of the storage circuit, the non-dimensional aspect ratio （length/thickness） and the non-dimensional end mass of the harvesting structure. The numerical results show that： （1） the power density can be optimized by varying the non-dimensional inductance for each fixed non-dimensional aspect ratio with a fixed non-dimensional end mass; and （2） for a fixed non-dimensional inductance, the power density is maximized if the non-dimensional aspect ratio and the non-dimensional end mass are so chosen that the harvesting structure, consisting of both the piezoelectric bimorph and the end mass attached, resonates at the frequency of the ambient acoustic source.     

Studies of a Magnetocumulative Source of Electromagnetic Pulses with a Double Inductive Energy Storage

An energy source based on a helical magnetocumulative generator with simultaneous initiation of an explosive charge on the axis was developed. The generator operates on a double inductive energy storage with current circuit breakers in each storage. The main analytical dependences of the pulse amplitude and shape on the parameters of the double inductive energy storage were obtained. In an experiment with such an energy source, a voltage pulse of 770 – 800 kV was obtained on a breaker made of electrically exploding wires. The voltage at possible load points was 1300 – 1350 kV. The duration of the voltage pulse edge from 0.1U _max to 0.9U _max did not exceed 0.5 sec.