简控火箭弹舵翼气动干扰特性研究

为了研究固定鸭舵简控火箭弹舵翼气动干扰特性,在验证数值方法适用性和可靠性的基础上,采用数值模拟方法对该弹气动特性进行仿真分析。计算得到不同弹长和不同舵翼相对夹角(鸭舵组件反旋角)工况下由鸭舵和尾翼产生的空气动力参数,仿真获得火箭弹外流场压力分布。研究分析了弹体长径比和舵翼相对夹角对鸭舵和尾翼气动特性的影响规律。结果表明:鸭舵与尾翼之间的气动干扰受弹体长径比影响,当弹体长径比达到一定数值时鸭舵对尾翼的气动干扰消失,且这种舵翼气动干扰特性对不同舵翼相对夹角情况同样适用; 研究结果可用于简化固定鸭舵火箭弹气动特性的研究方法,提高火箭弹气动外形设计效率。     

鸭式布局制导火箭弹气动特性数值计算

为分析气动外形对鸭式布局制导火箭弹气动特性的影响,设计了两种具有不同尾翼的制导火箭弹模型,以三维Navier-Stokes方程为控制方程,采用结构网格、k-ε模型对制导火箭弹的绕流场进行了数值模拟,得到了两种结构方案下制导火箭弹的气动特性参数.研究结果表明,相较于6片尾翼设计方案,采用4片尾翼设计方案的制导火箭弹具有更大的升阻比,且静稳定性更好.     

引信头锥摆动角对火箭弹气动特性及控制能力影响

针对低旋火箭弹在引信头锥摆动时改变了全弹的气动特性问题,进行了气动特性仿真,分析了引信头锥摆动角对火箭弹气动参数的影响,并利用气动仿真得到的数据进行控制能力的仿真,从而为弹道修正火箭弹设计提供依据。仿真结果表明:升力系数和俯仰力矩系数随引信头锥摆动角的增大都有显著的增大,且在稳定飞行时引信头锥摆动火箭弹的修正能力可以满足火箭弹二维弹道修正的要求。     

高旋火箭弹增程稳定性设计及气动特性分析

针对旋转稳定火箭弹提高射程和增大飞行速度带来的飞行不稳定问题,进行了基于稳定飞行的转速设计,并利用FLUENT软件和用户自定义函数UDF,在旋转壁面边界条件下对火箭弹进行气动特性仿真,分析了火箭弹阻力系数、升力系数和马格努斯效应随攻角的变化规律。结果表明:在设计转速为2827.43rad/s下,气动仿真和外弹道仿真结果能够满足火箭弹飞行稳定性要求,从而为火箭弹增程设计提供了依据。     

火箭弹快速空气动力计算模型研究

空气动力学计算是火箭弹散布与稳定性设计的基础，在初步设计阶段，常使用大量图表数据，应用十分不便。文中在开发火箭弹快速设计软件的背景下，利用数据拟合方法，对大量图表数据进行曲线拟合，拟合误差小于3．0％，平均误差小于1．0％，得到一系列气动曲线方程，大大简化了气动计算过程，对提高火箭弹的设计效率有重要的实际意义。     

大长径比低旋尾翼稳定火箭弹最佳转速的确定

为了提高射击精度和密集度，对于尾翼稳定火箭弹，一般都采用低速旋转的方式消除推力偏心、质量偏心和气动偏心等的影响。但低旋时火箭弹转速应避免共振转速．即保证出炮口后弹轴章动角迅速衰减；大长径比尾翼火箭弹在飞行时自身还会产生弹性随机振动，转速设计还应避开火箭弹的固有振动频率，以防止发生结构共振。文中采用ANSYS有限元软件计算火箭弹的固有振动频率和动力响应特性，并依据这些计算结果给出最佳转速的确定方法。     

高速箭弹滚转气动特性

为提高尾翼弹射击精度,对高速箭弹滚转气动特性进行研究。建立火箭弹简化模型,对不同翼片斜置角 的火箭弹进行数值模拟,采用有限体积法对空间进行离散,通过多参考系模型模拟火箭弹的定常旋转,得出火箭弹 的滚转阻尼力矩导数和平衡转速,并分别对有、无旋转条件下的气动特性进行分析。计算结果表明：火箭弹升力系 数随攻角的增大而增大,随翼片斜置角的增大变化不大;滚转阻尼力矩导数在高空时会骤减,平衡转速随着马赫数 的增大而增大。     

火箭弹不同尾翼气动特性分析及优化

主要介绍了固定翼、卷弧翼和马刀翼3种常用的尾翼结构,并分别对固定翼、卷弧翼及马刀翼这3种不同尾翼的火箭弹进行了气动特性分析,分析结果表明马刀翼具有较好的气动特性;并进一步对马刀翼进行了气动优化分析。     

有头部偏角的尾翼火箭弹气动性能数值计算

运用通用流体计算软件CFX对有头部偏角的尾翼火箭弹气动特性进行了数值计算.计算了不同头部偏角和弹体攻角姿态时,在不同马赫数下火箭弹所受的空气动力,分析表明超音速飞行时抛物外形大长径比弹头相对弹体有一定转角时能产生较大的控制力和力矩.文中的计算分析可为发展弹道修正制导火箭弹提供理论基础.     

高速火箭弹不同防热方案对气动加热影响规律的研究

采用工程算法与数值算法相耦合的气动热计算方法进行高超声速火箭弹的气动热参数计算。对火箭弹边界层外缘参数采用无黏数值算法求取,对边界层内黏性起主导作用的区域采用工程算法计算。由于防热层厚度方向特征尺寸远小于火箭弹表面特征尺寸,对防热层的气动热计算进行了一维简化并建立了一维非稳态导热微分方程。在确定防热层边界条件后,经过导热微分方程的求解得到了长航状态下火箭弹防热层的温度分布。通过对防热层的不同物性参数的研究,得出防热层物性参数对气动加热的影响规律,为气动热防护问题的研究提供了参考。     

Nitrosation and Nitration of Tetraacetyldibenzylhexaazaisowurtzitane

Tetraacetyldibenzylhitane (TADBIW) was subjected to debenzylation by nitrosating with inorganic materials available commercially to synthesize tetraacetyldinitrosohexaazaisowurtzitane (TADNSIW). TADNSIW was purified, and its structure was determined by FTIR, 1H NMR, MS and element analysis. The debenzylation reaction of TADBIW gave quantitative benzaldehyde as a by-product. This indicates that the reaction produces an imine cation as an intermediate. Hexanitrohexaazaisowurtzitane (HNIW) was prepared from unpurified TADNSIW with the yield over 96.0 % and the purity more than 98.0 %. And the mechanism of the reaction from TADNSIW to HNIW is proposed to be oxidation of nitroso and nitration of acetyl on the molecule of TADNSIW, This reaction system involved is simple, and the reaction can complete within a short time and under mild conditions. The product can be easily to separate and the waste disposed readily.     

Method for Measuring Velocity of Warhead Fragments Based on Photoelectric Detection

For measuring velocity and impacting position of single fragment of warhead, a non-contact measuring method is proposed, in which a six-light-screen array, a position indicator, a multi-channel chronograph and a computer are used.The principle of measurement is described. The key device of the system is a light screen array sensor which consists of six light screens allocated with certain geometrical parameters. When the fragment flies through the light screen array, the time of passing through each of the screens is recorded by the multi-channel chronograph. According to the time data and the geometrical parameters of the array, the velocity vector and the location of the fragment can be calculated immediately. The presented method can be used to locate the fragment and to measure the real velocity on its flying direction. It can also be used to measure the velocity of a fragment swarm after the system is engineered further.     

A Robust Algorithm for Watermarking 2D Vector Maps with Low Shape-Distortions

The technique of watermarking has been introduced into 2D vector maps for many potential applications such as protecting the copyright of important GIS （geographical information system） data and tracing the data source of military maps. In most previous works, although the validity of the map data could be preserved during the embedding procedure, the shape-distortions of the map elements are usually neglected which would tend to degrade the invisibility of the watermarking schemes. A shape-preserving algorithm for watermarking 2D vector maps is presented in this paper. A 1D distance sequence extracted from the original map is adopted as the cover data instead of 2D coordinates. A watermark bit is represented by changing the distributions of the cover data. The embedding procedure induces lower shape-distortions than in former works. Experimental results indicate better invisibility of the proposed scheme, as well as its robustness to certain attacks such as map simplification, interpolation, additive noise and most geometric transforms.     

数码电子雷管中影响点火头性能因素分析

阐述了数码电子雷管中,点火药剂细结晶三硝基间苯二酚铅（LTNR）的制备工艺;从点火药剂的种类、加入黏合剂的质量分数、桥丝直径、点火头的电阻值、防潮漆的蘸涂等方面对点火头性能的影响因素进行了探讨;通过震动试验、并联起爆试验、延期精度检测与考核,试验结果表明：一次性合成的细结晶LTNR是制造数码电子雷管点火头较为理想的点火药剂,按技术要求生产的点火头性能指标能够满足行业标准要求。     

Open Rule-setting System Applied to Conceptual Design of Engines

Open rule-setting method advanced in this paper concentrates on providing designers of engines with a convenient way to express their design innovations and develop the expected prototypes in the early CAD stage, and constitute effective models for the following analysis process of CAE and CAPP. The problems arisen in the process of conceptual design with the traditional experience-based development method are analyzed. Based on those analyses, open rule-setting method is presented and some associated technical problems are discussed. The functional framework of open rule-setting system was built as software engineering methods. The speciality of the engine product as a kind of complex product and the requirement of the engine product based on its structural particularity to rule-setting system are considered carefully. A demonstration is supplied to illustrate how the open rule-setting method enhances the efficiency and quality of the engine conceptual design.     

Research on Linux Network Device Driver

By analyzing the working principle of Linux network device driver, discussing the Linux network driver structure and its key technologies, the general network driver structure and its design methodologies in Linux system are summarized. Through modifying the network device driver of Linux device driver 3rd version snull, c and improving the COW technology, the Zero-Copy technology in Linux （kernel version 2.6.11 ） is implemented. In the end, the success test tells us that the thorough analysis of network device driver is the foundation of many applications, and it also provides a certain improvement to a lot of real applications, even to military application development.     

Design and Implementation of One Missile Visual Simulation System Based on OpenGL

The implementation of a missile＇s visual simulation system is explained that is developed with OpenGL（open graphic library） and the flight path and flight carriage in different stages of the missile are displayed. The establishment problems of the 3D scene are circumstantiated including the construction and redeployment of the model, creation of the virtual scene, setting of the multi-viewports and multi-windows etc. The missile＇s data driver, system flow, the modules and their mutual relations of the missile visual simulation system are discussed. The missile flight simulation results and effect of the scenes are given.     

Improvement and Experiment of the Reamer in Vibra Cutter Against Wave Edge of Titanium Sheet Alloy Parts

By analyzing the influencing factors of part quality making of sheet alloy of titanium by vibra cutter, the shape of upper reamer is set as cylinder and wedge-shaped form, and the lower reamer as plain and hemicycle form, and its main structural parameters are defined as well. Then it is validated further that such improved vibra cutter reamer can be used to process curve-edged parts of titanium alloy sheet. The experimental result shows that the titanium alloy sheet parts processed by above equipment have no sharpen angles for convex parts and evident crevasse of concave-edged part. In summary, such improvement can eliminate the free-waved edge and improve the manufacture quality of titanium alloy sheet parts greatly.     

Dynamic Encryption Technology in Ad-hoc Networks

A new dynamic encryption application in ad-hoc networks is proposed. The advantages of this method are its being able to use the previous ciphertext as a seed of a new encryption process, rendering the encryption process effective in all communication process by continuous dynamic key generation together with synchronization, and its capability to cut back on system bandages to a greater extent, which is valuable for the ad-hoc circumstance. In addition, the rationality and effectiveness of this novel encryption method have been verified by the test results.     

Experimental Study on the Small Flyer Initiating Behavior of Fine-grained Explosives

The initiating behavior of fine-grained explosives by small flyer is studied. The diameter of small flyer in this device is 1 ram. The test results indicate that the granularity of explosives has great effect on its flyer initiating sensitivity.The flyer initiating sensitivity of the fine-grained explosives is higher and the critical initiating energy is lower than that of common explosives. For common explosive, the flyer initiating sensitivity increases as the density is reduced. But for the fine-grained explosive, the test results are exactly opposite.