不同炸药及装药高度对聚能射流侵彻性能的影响

为研究不同炸药及装药高度对聚能射流侵彻性能的影响,分析不同炸药及装药高度对聚能射流侵彻性能的影响.通过 TrueGrid 建模,LS-DYNA 数值模拟计算,对在同一装药直径、装药高度时,不同炸药对聚能射流头部速度、侵彻后效靶板的能力进行对比;比较在同一装药直径、同种炸药时,不同装药高度对聚能射流头部速度、侵彻后效靶板的能力.仿真结果表明:奥克托今炸药压垮药型罩形成的聚能射流头部速度最大,侵彻后效靶板能力最强;装药高度的变化对奥克托今炸药压垮药型罩形成的聚能射流的头部速度,侵彻后效靶板的能力影响不明显.该研究结果对聚能装药设计具有一定参考价值.     

聚能射流的水下成型及毁伤效果

为分析聚能射流在水介质中的运动规律、形态变化及对靶板的毁伤效果,对锥角药型罩结构的聚能战斗部形成的聚能射流进行数值仿真模拟.在考虑静水压力的条件下,用AUTODYN对聚能射流在水下1、10和50 m侵彻水介质时的形态变化、速度衰减及对靶板的侵彻效果进行了数值模拟,并与相同炸高下空气中形成的射流进行对比.结果表明:射流头部会随着水深的加深发生明显的堆积现象;速度在空腔中呈线性规律衰减,在水介质中呈指数规律衰减;相同炸高条件下,水中的聚能射流对靶板的侵彻孔径比空气中大.     

大锥角聚能装药射流形成及对钢靶侵彻的数值模拟

为了研究大锥角聚能装药射流形成和对钢靶侵彻过程中的一些特性,采用AUTODYN软件,对锥角聚能装药射流形成及侵彻钢靶过程进行了数值模拟。模拟结果表明:大锥角聚能射流是药型罩在爆轰波的作用下向后反转形成的漏斗型密实射流,其在飞行过程中,速度基本保持不变,而在侵彻钢靶时,侵彻速度和动能都迅速下降,直到再也不能侵彻钢靶为止。将数值模拟结果与实验结果进行了对比分析表明:数值模拟结果与实验结果相一致。     

聚能射流对间隔靶板的侵彻深度模型及数值模拟研究

建立聚能装药射流垂直/斜侵彻间隔靶板的深度公式,完善聚能射流对间隔靶板的侵彻深度模型。并对其侵彻间隔钢靶板过程进行数值模拟,分析聚能射流和间隔钢靶板的形貌,说明间隔钢靶板法线与聚能射流夹角对射流干扰影响的基本规律,即夹角越大干扰效果越明显。当间隔钢靶板法线与聚能射流夹角为0°和60°时,聚能射流侵彻深度的理论和数值模拟结果基本一致,说明聚能射流侵彻间隔靶板的深度模型基本正确。     

炸高对线型聚能切割器切割深度影响的数值分析

根据聚能装药射流形成和断裂原理,使用autodyn2d对线型聚能切割器侵彻靶板的物理过程进行了数值仿真.针对不同炸高的4组模犁,详细讨论了炸高对射流侵彻能力的影响.研究结果表明:小炸高下,影响射流侵彻能力的主要因素是靶板阻碍了药型罩后部的压垮;大炸高下,射流与靶板的作用存在着二次侵彻的现象,具体侵彻效果与炸高有关.从工程目的出发,可以选取射流头部第2次断裂时所处的位置为有利炸高.     

活性药型罩聚能装药侵彻爆燃试验及耦合作用机理分析

为研究氟聚物基活性药型罩聚能装药对钢靶的侵彻爆燃行为及耦合作用机理，开展配方为质量分数73.5%聚四氟乙烯(PTFE)/26.5%Al活性药型罩聚能装药作用钢靶静爆实验，获得炸高对侵彻深度、侵彻孔径、钢靶爆裂行为影响特性。实验结果表明，活性药型罩聚能装药炸高在0.35～1.00倍装药直径范围内，对钢靶侵爆耦合毁伤效应最为显著。结合准定常理想不可压缩流体力学理论，引入活性射流反应延迟时间，给出活性射流侵彻深度与反应延迟时间函数关系，建立活性射流侵孔内有效质量模型；基于修正的伯努利方程，结合活性射流内爆特性，发展活性射流侵孔孔径理论模型；结合圆筒破坏理论提出活性射流侵爆耦合作用下钢靶爆裂行为判断方法。理论模型定量化描述了活性射流对钢靶的侵爆行为，揭示了破甲终止后活性射流内爆超压导致的扩孔与钢靶爆裂机理。     

超聚能射流成型及侵彻混凝土的数值模拟研究

为了提高聚能装药对混凝土介质的毁伤威力,设计了一种新型的截顶形超聚能装药结构,对其成型过程进行数值仿真,分析了超聚能射流的成型特点,以及不同炸高下射流对混凝土靶板的侵彻规律。研究表明:新型的截顶形超聚能装药结构可以形成杵体较少、头部成细锥形的不断裂高速射流,侵彻混凝土靶板时既可以保证一定的侵彻深度又可以在靶板表面形成漏斗形破坏区。该装药结构形成的超聚能射流头部速度达到13km/s以上,具有侵彻能力的射流质量占药型罩质量的66.02%。炸高为3倍装药口径时,射流对混凝土靶板的侵彻深度达到10倍装药口径,漏斗坑直径达到0.5倍装药口径。     

聚能杆式射流侵彻混凝土和岩石靶体试验与数值模拟

为研究聚能杆式射流成型及其对混凝土和岩石靶体的侵彻破坏特性，分别开展了大隔板聚能装药射流成型X光试验及侵彻混凝土和岩石靶试验。同时，利用ANSYS/AUTODYN有限元软件，针对大隔板聚能装药爆轰波演化过程、杆式射流成型及侵彻混凝土和岩石过程进行了数值模拟，结合试验结果分析了聚能杆式射流对混凝土和岩石靶体的侵彻毁伤特性。研究结果表明：大隔板聚能装药炸药采用Lee-Tarver状态方程能够较为准确的描述爆轰波的传播过程，射流参数（侵彻体长度、射流长度、射流头部速度和射流直径）与试验相比最大误差为12.8%。大隔板聚能装药起爆后可形成大长径比的杆式射流，侵彻后的混凝土和岩石靶中均有明显的开坑区，但侵彻混凝土过程中扩孔作用不明显。其中，侵彻试验中混凝土靶形成的侵彻深度和侵彻孔径相较于岩石靶分别提高了46.7%和48.1%，而岩石靶表面破坏程度和开坑区域均大于混凝土靶。与混凝土靶相比，由于射流侵彻岩石靶过程中裂纹的不断扩展，形成的裂纹长度和宽度均大于混凝土靶，因此靶体损伤范围较大，内部破坏严重。     

炸高对环形聚能射流侵彻特性的研究

为研究炸高对环形聚能射流侵彻特性的影响,采用LS-DYNA有限元程序及Lagrangian-Eulerian流固耦合算法,对截面对称的小口径环形聚能切割器在不同炸高条件下射流成形及侵彻靶板的物理过程进行数值模拟,重点讨论炸高对切口对称性及侵彻深度的影响。数值模拟结果表明:在侵彻过程的3个阶段,射流依次经历了头部射流垂直侵彻、杵体偏向内壁运动、杵体偏向外壁运动的形态变化;随炸高增大,射流和杵体的偏离越明显,切口越不对称,切口截面形状依次为"漏斗形"、"葫芦形"、"椭圆形";基于工程实际运用,可选取射流发生二次断裂的位置作为最佳炸高。     

聚能射流侵彻装甲钢的计算分析

该文以研究聚能射流侵彻装甲钢的过程为目标,借助ATOS-M模型计算了聚能射流侵彻靶体的过程及其靶内的运行轨迹,并得出相应的曲线图;通过对某装药结构侵彻装甲钢的模拟仿真,得出了射流侵彻靶体的过程曲线;通过切割分析试验后靶板内入孔的剖面形状,得出了射流在靶体内的运行轨迹曲线。结果表明:ATOS-M模型的计算结果与模拟仿真及试验结果吻合较好,说明ATOS-M模型可有效预测射流侵彻装甲钢的过程。     

Stability of the Third Generation Intensifier under Illumination

The stability under illumination of transmission-mode GaAs photocathode sealed in the third generation intensifier is investigated by use of spectral response testing instruments. The variations of spectral response with the illumination times under weak and intense illumination are compared. The variations of photoemission performance parameters are also characterized. The results show that during initial several weak illuminations photocathode behaves no evident decay and a maximum sensitivity is achieved, while under intense illumination the sensitivity of photocathode begin to decrease largely at the first illumination. The calculated performance parameters show that the variation of surface escape probability with illumination times is a direct cause of instability of photocathode. It is also found that under intense illumination peak wavelength is moved towards short-wave and peak response is decreased, which shows that the ability of long-wave response of photocathode is decreased.     

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.     

Passive Acoustic Radar for Detecting Supersonic Cruise Missile

A Passive Acoustic Radar is presented as a necessary complement to electromagnetic wave radar, which will be expected to be an effective means for detecting cruise missiles. Acoustic characteristics of supersonic flying projectiles with diverse shapes are expounded via experiment. It is pointed out that simulation experiment could be implemented using bullet or shell instead of cruise missile. Based on theoretical analysis and experiment, the ““acoustic fingerprint““ character of cruise missile is illustrated to identify it in a strong noise environment. After establishing a locating mathematical model, the technique of acoustic embattling is utilized to resolve a problem of confirming the time of early-warning, considering the fact that velocity of sound is much slower than that of light. Thereby, a whole system of passive acoustic radar for detecting supersonic cruise missile is formed.     

Algorithm for Multi-laser-target Tracking Based on Clustering Fusion

Multi-laser-target tracking is an important subject in the field of signal processing of laser warners. A clustering method is applied to the measurement of laser warner, and the space-time fusion for measurements in the same cluster is accomplished. Real-time tracking of multi-laser-target and real-time picking of multi-laser-signal are introduced using data fusion of the measurements. A prototype device of the algorithm is built up. The results of experiments show that the algorithm is very effective.     

Super-resolution Restoration of Remote-sensing Images

A novel image restoration scheme, which is super-resolution image restoration algorithm Poisson-maximum-afterword-probability based on Markvo constraint （MPMAP） combined with evaluating image detail parameter D, has been proposed. The advantage of super-resolution algorithm MPMAP incorporated with parameter D lies in the fact that superresolution algorithm MPMAP model is discrete, which is in accordance with remote-sensing imaging model, and the algorithm MPMAP is proved applicable to linear and non-linear imaging models with a unique solution when noise is not severe. According to simulation experiments for practical images, super-resolution algorithm MPMAP can retain image details better than most of traditional restoration methods; at the same time, the proposed parameter D can help to identify real point spread function （PSF） value of degradation process. Processing result of practical remote-sensing images by MPMAP combined with parameter D are given, it illustrates that MPMAP restoration scheme combined PSF estimation has a better restoration result than that of Photoshop processing, based on the same original images. It is proved that the proposed scheme is helpful to offset the lack of resolution of the original remote-sensing images and has its extensive application foreground.     

Design and Simulation of TF and TA Controller for Missile

A nonlinear terrain following(TF) and terrain avoidance(TA) controller is proposed for missile control systems. Based on classical TF algorithm (adaptive angle method), a new method for TF controller is proposed by using angle of attack. A method of obtaining terrain outline data from digital elevation map (DEM) for TF control is discussed in order to save store space. A TA algorithm is proposed by using bank-to-turn technique. The block control model, which is suitable for backstepping design, is given for nonlinear model of missile. Making full use of the characteristics of the system and combining block control principle and backstepping technique, a robust controller design method is proposed. Uncertainties in every sub-block are allowed, and can be canceled by using the idea of nonlinear damping. It is proved that the state tracking errors are converged to a neighborhood of the origin exponentially. Finally, nonlinear six-degree-of-freedom simulation results for the missile model are presented to demonstrate the effectiveness of the proposed control law.     

Design and Analysis of Test Schemes of Static Postponing Time on Shrapnels Used to Riot Control

The test scheme of static postponing time given in our actual national military test standard on shrapnels used to control riot is a nine-point test scheme on the combined action of three kinds of temperatures and three kinds of pressures,the consumed ammunitions are more excessive. Statistic analysis and tentative checkout about a lot of test data are done,feasibility gists are put forward for optimizing of the test design scheme. The optimizing design and data analysis of test scheme of the item are done by managing uniformity design theory, two scientific and reasonable six-point test schemes are confirmed. The feasibility and reliability of the optimizing design schemes put forward above are proved ulteriorly by test validating. The gained schemes not only have good design uniformity and little ammunition wastage and meet the test demand, but also have better forecast ability for the result data of other points using the mathematic models from the actual test points.     

Influence of Installing Error on the Surface Shape Precision of the Axial Symmetry Aspheric Workpiece in Lapping

A method to calculate the surface shape error, which is caused by the installing error between the workpiece and the lapping tool in the process of form lapping, is proposed. The mathematical model which the installing translation error influences on the workpiece surface shape error is established. The changing rule of the error is simulated through the calculating example of the paraboloid workpiece. The results indicate that the surface shape error of the workpiece is increasing with the increase of the installing translation error, it is also increasing gradually along the center point of the curve surface to the edge, and the influence is severer to the curve surface with great curvature than that of the small curvature when the translation error is the same.     

Experimental Research on Output Performances of Giant Magnetostrictive Actuator

The paper introduces the performances of magnetostrictive actuators and its applications, discusses the design methods for the structure and internal magnetic circuit of a giant magnetostrictive actuator, and makes tests on the output displacement and force characteristics for an actuator using homemade magnetostrictive material. The experimental result shows that the actuator has satisfactory output precisions and ranges in transient and stable states, and can be used in lowfrequency vibration control system of precise equipment.