膛内等离子体点火及燃烧增强过程数值模拟

在初始点火过程中 ,假设等离子体为充分发展射流流动 ,因而可采用积分近似模型进行描述。而在随后的膛内燃烧过程中通过以经验公式给出等离子体混合长度的方法来处理等离子体的运动 ,并给出了合适的相间阻力及传热公式。通过在计算网格设计中引入了自适应方法提高了数值解精度。计算膛压曲线与实验符合良好。相对常规内弹道情形 ,等离子体能量的注入使在不同时刻膛内的气、固两相速度、压力和膛底温度等出现提高 ,这是等离子体注入后对内弹道的增强过程。计算结果为固体工质电热化学炮的弹道设计提供了理论依据。     

等离子体点火密闭爆发器中火药燃速特性的研究

等离子体与火药的作用规律是影响电热化学发射中能量利用效率的关键因素。研制了采用等离子体点火的密闭爆发器实验系统,对单基药在等离子体作用下的燃烧特性进行了研究。结果表明:等离子体点火可以显著缩短火药的点火延滞时间;实现有效点火的电能的最低阈值低于0.05kJ/g;输入电能可以显著增加火药的燃速。等离子体对所用单基药燃速的增强效果仅体现在电脉冲注入期间,但是随着电能输入的增加,逐渐显示出等离子体注入期后火药燃速增强的趋势。     

激光干涉诊断ETC发射装置产生的等离子体射流

叙述了用光楔错位干涉与高速摄影技术诊断电热化学（ＥＴＣ）发射装置中等离子体发生器产生的等离子体射流的方法，研究了等离子体射流与毛细管几何尺寸以及电源供能的关系。该方法有助于改进电热化学发射装置中等离子体发生器的设计及其效能的提高。     

THREE DIMENSIONAL STRESS ANALYSIS OF SYMMETRIC COMPOSITE LAMINATES UNDER UNIAXIAL EXTENSION AND IN－PLANE PURE SHEAR

ＴＨＲＥＥＤＩＭＥＮＳＩＯＮＡＬＳＴＲＥＳＳＡＮＡＬＹＳＩＳＯＦＳＹＭＭＥＴＲＩＣＣＯＭＰＯＳＩＴＥＬＡＭＩＮＡＴＥＳＵＮＤＥＲＵＮＩＡＸＩＡＬＥＸＴＥＮＳＩＯＮＡＮＤＩＮ－ＰＬＡＮＥＰＵＲＥＳＨＥＡＲＣｈｉｃｎｗｅｉ－ｚａｎｇ（钱伟长）,Ｈｕａｎｇ...     

PARETO EQUILIBRIA OF MULTICRITERIA GAMES WITHOUT COMPACTNESS，CONTINUITY AND CONCAVITY

ＰＡＲＥＴＯＥＱＵＩＬＩＢＲＩＡＯＦＭＵＬＴＩＣＲＩＴＥＲＩＡＧＡＭＥＳＷＩＴＨＯＵＴＣＯＭＰＡＣＴＮＥＳＳ,ＣＯＮＴＩＮＵＩＴＹＡＮＤＣＯＮＣＡＶＩＴＹＤｉｎｇＸｉｅｐｉｎｇ（丁协平）Ａｂｓｔｒａｃｔ：Ｉｎｔｈｉｓｐａｐｅｒ．ｂｙｕｓｉｎｇａｍｉｎ...     

THE TEMPERATURE ANALYSIS OF THE BILLET WITH PHASE CHANGE DURING CONTINUOUS CASTING

ＴＨＥＴＥＭＰＥＲＡＴＵＲＥＡＮＡＬＹＳＩＳＯＦＴＨＥＢＩＬＬＥＴＷＩＴＨＰＨＡＳＥＣＨＡＮＧＥＤＵＲＩＮＧＣＯＮＴＩＮＵＯＵＳＣＡＳＴＩＮＧＺｈａｏＸｉｎｇ－ｈｕａ（赵兴华）,ＣｈｅｎｇＸｉａｏ－ｄｉ（陈小弟）（ＳｈａｎｇｈａｉＵｎｉｖｅｒｓｉｔｙ...     

An analysis of the post-buckling of laminated plates of symmetric cross-ply

ＡＮＡＮＡＬＹＳＩＳＯＦＴＨＥＰＯＳＴ－ＢＵＣＫＬＩＮＧＯＦＬＡＭＩＮＡＴＥＤＰＬＡＴＥＳＯＦＳＹＭＭＥＴＲＩＣＣＲＯＳＳ－ＰＬＹＷｅｎｇＺｏｎｇｙｉ（翁宗诒）（ＲｅｃｅｉｖｅｄＭａｒｃｈ６,１９９５,ＣｏｍｍｕｎｉｃａｔｅｄｂｙＺｈｏｕＣｈｅｎｇｔ...     

EQUILIBRIUM IN ABSTRACT ECONOMICS WITH A NON－COMPACT INFINITE DIMENSIONAL STRATEGY SPACE

ＥＱＵＩＬＩＢＲＩＵＭＩＮＡＢＳＴＲＡＣＴＥＣＯＮＯＭＩＣＳＷＩＴＨＡＮＯＮ－ＣＯＭＰＡＣＴＩＮＦＩＮＩＴＥＤＩＭＥＮＳＩＯＮＡＬＳＴＲＡＴＥＧＹＳＰＡＣＥＤｉｎｇＸｉｅ－ｐｉｎｇ（丁协平）（ＳｉｃｈｕａｎＮｏｒｒｎａｌＵｎｉｖｅｒｓｉｔｙ,Ｃｈｅｎ...     

二乙基二硫代氨基甲酸镧配合物润滑脂添加剂的摩擦学研究

在空气环境下，制备了一种二基二硫代氨基甲酸与稀土元素镧的配合物（ＥＬａＤＴＣ）。利用四球试验机评价了其在通用锂基润滑脂中的极压和抗磨损性能，并与常用二烷基二硫代磷酸锌（ＺＤＤＰ）进行了对比。结果表明：此类稀土配合物能够显著提高锂基润滑脂的极压性能，且优于ＺＤＤＰ；同时具有良好的抗磨损性能，在添加质量分数为１％时ＥＬａＤＴＣ的抗磨损效果优于ＺＤＤＰ。采用ＸＰＳ对ＥＬａＤＴＣ的极压抗磨机理进行了分析，     

Relativistic absoluteness of time-space-moving mass

ＲＥＬＡＴＩＶＩＳＴＩＣＡＢＳＯＬＵＴＥＮＥＳＳＯＦＴＩＭＥ－ＳＰＡＣＥ－ＭＯＶＩＮＧＭＡＳＳＣｈｉｎＹｕａｎｓｈｕｎ（秦元勋）（ＩｎｓｔｉｔｕｔｅｏｆＡｐｐｌｉｅｄＭａｔｈｅｍａｔｉｃｓＡｃａｄｅｍｉａＳｉｎｉｃａＣｈｉｎａ,Ｂｅｉｊｉｎｇ１０００...     

多孔发射药等离子体增强燃速

利用密闭爆发器实验系统进行了等离子体增强4/7高固体发射药燃速特性的实验研究。采用等离子体发生器的电能利用效率来表征密闭爆发器内输入的等离子体能量,拟合了考虑压力梯度影响和电功率增强的固体发射药瞬态燃速公式。根据实验数据得到4/7高固体发射药的电功率燃速增强因子为0.005 MW-1。与Woodley燃速公式相比,瞬态燃速公式与实验压力曲线符合程度更高,能够更精确地描述固体发射药在等离子体作用下的燃烧过程。     

基于光学诊断的某新型含铝推进剂燃烧特性分析

为探究某新型含铝固体推进剂燃烧特性和规律，在模拟固体发动机的高压条件下，采用可调功率激光器结合高速摄影、发射光谱等光学诊断技术对该新型含铝固体推进剂开展了系统的点火及燃烧过程研究。通过对该推进剂的点火延迟、退移速率、燃烧温度以及团聚物颗粒尺寸的定量测量和分析，明确了该推进剂的点火延迟量级；证实此推进剂的退移速率严格遵循Summerfield燃速公式；判断出其最高燃烧温度高于3 300 K，且随压力增大而升高；通过对燃烧过程中发光凝聚相产物面积的量化分析得出推进剂产物中团聚物粒径尺寸受环境参数的影响规律。     

Ignition of solid propellants

At present, the study of solid-propellant ignition is of particular interest owing to the adoption of hybrid motors [1–3]. The status of experimental and theoretical research in this field can be evaluated on the basis of the rather extensive survey of American papers in [2]. It is noteworthy that a common deficiency in available references is the absence of exact ignition criteria; in most cases the propellant is assumed to have ignited when its surface temperature reaches a prescribed level (gasification temperature), or when the rate at which the temperature increases with time at the propellant surface is sufficiently high. Exact criteria for this rate, however, are not given. In this article, we present ignition criteria for solid propellants and these are based on a diffusion-burning model. It is shown that for a diffusion flame to exist above the propellant surface, two conditions must be satisfied simultaneously: 1) the propellant surface temperature must equal the gasification temperature for that propellant and 2) the temperature gradient at the surface must be smaller than some value which depends on the kinetics of the chemical reaction in the diffusion flame and on the rate of oxidizer input to the propellant surface during burning.Two ignition techniques are examined as examples: ignition by hot gases or radiant heat flow and ignition by means of an active film which reacts with a cold oxidizer; the film is applied to the propellant surface prior to ignition.     

Numerical modeling of the processes within the combustion chamber of a solid propellant rocket engine during the stabilization of the design operation mode

Comprehensive numerical modeling of the processes occurring in the combustion chamber of a solid propellant rocket engine during the stabilization of the design operation mode is performed. The self-consistent problem considered includes nonstationary operation of an ignition device, warmup and ignition of a solid propellant charge followed by its nonstationary burning, nonstationary threephase homogeneous-heterogeneous flow of the combustion products in the combustion chamber, in the nozzle, and behind the engine nozzle unit, engine depressurization, and nozzle unit plug blowing-out. The results of the calculations are presented.     

考虑自然对流的某固体火箭发动机慢速烤燃特性数值分析

针对某高氯酸铵/端羟基聚丁二烯(AP/HTPB)推进剂固体火箭发动机，采用两步总包反应描述AP/HTPB的烤燃过程，建立了考虑发动机空腔自然对流的二维轴对称烤燃模型，对加热速率分别为3.6、7.2和10.8 K/h时火箭发动机的慢速烤燃行为进行了数值预测，研究了该火箭发动机的热安全性问题。结果表明，固体火箭发动机空腔内的自然对流对AP/HTPB推进剂的着火温度、着火延迟期和着火位置有一定影响，在热安全性精确分析中不可忽略。3种加热速率下，AP/HTPB推进剂的最初着火位置均出现在药柱肩部的环形区域内，3种加热速率对应的着火延迟期、着火温度及着火时壳体温度分别为30.71、20.06、18.68 h，526.52、528.10、530.64 K，和479.56、496.82、508.77 K。随着加热速率的增大，烤燃响应区域向推进剂与绝热层交界处移动，着火位置的二维截面由椭圆形变为半椭圆形。     

Nonstationary burning of propellants with variable surface temperature

The author examines nonstationary processes (combustion at varying pressure, quenching, and ignition) for a model propellant whose burning rate u and surface temperature t₁ depend on pressure p and initial temperature T₀. All the processes in the surface reaction zone and the gas phase are assumed inertialess. It is shown that a theory of nonstationary combustion for such a model can be constructed by analogy with the Zel'dovich theory [1, 2], in which the surface temperature of the powder is assumed fixed. The variation of burning rate with time has been investigated for small sudden pressure changes. It is shown how a sufficiently large and steep pressure drop may cause quenching of the propellant. The process of propellant ignition is subjected to a qualitative analysis.The author thanks O. I. Leipunskii, A. G. Istratov, V. B. Librovich, and A. D. Margolin for their comments and advice.     

主控提前点火对复合推进剂慢速烤燃响应的影响

为研究主控点火对复合推进剂慢速烤燃响应特性的影响,设计并开展了典型复合推进剂装药慢速烤燃实验,结合数值计算和推进剂热分解失重及形貌演化过程,探讨了点火前推进剂内的温度分布情况及推进剂细观结构热损伤规律。研究发现:针对复合推进剂装药的慢速烤燃,在推进剂发生自热点火前温度较低时进行主控点火可以有效降低反应剧烈程度;随着加热温度的升高,推进剂中部分组分发生分解,导致推进剂内部温度高于壳体温度,同时推进剂中粘结剂及AP的分解会导致推进剂装药形成多孔状的结构,在点火后更易导致对流燃烧,加剧反应烈度;当壳体温度仅138 ℃时,推进剂温度最高点达到150 ℃,最高点首先出现在靠近喷管的尾部,考虑到粘结剂及AP部分分解导致的孔隙结构会加剧反应的响应烈度,主控点火温度应设定在138 ℃以下。     

Fracture of a burning solid propellant attenuated by a crack-type cavity

A plane steady problem of fracture mechanics for a burning deformable solid propellant attenuated by a crack-type cavity with a burning surface is considered. The crack-type cavity is assumed to have tip zones with bonds between the faces, and mixed boundary conditions are imposed on the propellant charge boundary. The problem of equilibrium of a propellant charge containing a crack-type cavity reduces to solving a system of nonlinear singular integrodifferential equations with a Cauchy-type kernel. Based on the solution obtained, the normal and tangential forces in the tip zones of the crack-type cavity are found. Local conditions determining stability (safety) of the solid propellant burning regime are found.     

Solid propellant combustion in the presence of photoirradiation

Previous studies of the nonsteady processes associated with the irradiation of propellants with light have chiefly been devoted to the question of ignition [1–3]. It is also important to consider the effect of such an easily controlled influence as light on the propellant combustion process. We have attempted to estimate the dependence of the propellant burning rate on the intensity of the luminous radiation. Cases of steady-state combustion and combustion in the presence of a light flux varying harmonically with time are considered. It is assumed that the incident light flux is absorbed in the solid phase in accordance with the Bouguer-Lambert exponential law with constant transparency index. Steady-state combustion is considered within the framework of the Zel'dovich theory [4]. It is shown that in the steady state irradiation is equivalent to a certain increase in the initial temperature of the propellant. In the case of combustion with irradiation this makes it possible to use the data on steady-state combustion without irradiation. Nonsteady combustion in the presence of a periodically varying light flux is described with the aid of the Novozhilov model [5]. A correction to the mean burning rate (u °), proportional to the square of the light flux amplitude, is obtained. In the case of an exponential dependence of the burning rate on initial temperature the correction u ° is negative. The effect of irradiation on the stability of the steady-state propellant combustion mode is discussed.Translated from Zhumal Prikladnoi Mekhaniki i Tekhnicneskoi Fiziki, No. 5, pp. 70–77, September–October, 1971.In conclusion the authors thank O. I. Leipunskii and V. B. Librovich for their valuable advice.