配方参数对镁基水反应金属燃料/水蒸汽反应特性的影响

采用可视化燃烧实验器模拟发动机的水蒸汽环境,用高速摄影拍摄燃料在水蒸汽中的燃烧过程,并用热电偶测温,研究了燃料配方参数对镁基水反应金属燃料/水蒸汽反应的影响规律.研究结果表明,镁基水反应金属燃料与水反应分快速反应和慢速反应两阶段,反应速率随时间和反应程度的增加而降低;镁基水反应金属燃料/水反应的快速反应时间和反应程度是...     

氧化性气氛中镁颗粒燃烧特性研究进展

归纳总结了镁颗粒在空气、O₂、CO、CO₂和H₂O(g)中的燃烧特性。不同燃烧产物对二次反应和燃烧速率有不同的影响。基于对镁颗粒燃烧现象和产物分析,镁颗粒经历了从表面多相反应到气相燃烧的过程,镁颗粒着火阶段表面氧化层是由表面多相氧化反应形成,燃烧阶段中表面氧化层是由气相燃烧产物凝结或烧结、氧化层表面吸附反应和Mg-O溶液的相位分离等形成; 根据镁颗粒在不同氧化性气氛中的燃烧特性,介绍、评述了镁颗粒在空气或O₂、CO₂和H₂O(g)中的燃烧模型。镁颗粒在各种氧化性气氛中燃烧研究需要对反应机理深入研究; 燃烧模型中需丰富燃烧过程的物理化学信息,如反应的机理、化学动力学特性和表面氧化层对燃烧过程中传热传质的影响等。      

基于流动与化学反应耦合的镁/聚四氟乙烯烟火剂二维燃烧模型及数值计算

针对镁/聚四氟乙烯(MT)烟火剂燃烧过程中湍流对燃烧的影响关系,建立流动与化学反应相耦合的二维计算流体力学模型,模拟不同质量比MT烟火剂稳态燃烧过程,获得了燃烧场温度、组分分布特性,并将计算结果与文献\[10,16,18\]值进行对比。对比结果表明：燃烧场温度上升段大约20 mm, 这与文献\[10\]实验值吻合较好,且温升段距离与反应机理C₂F₄+M2CF₂+M区域位置相对应;当量质量比为33/67的MT火焰温度最高,与热力计算结果相一致,随着质量比的增加,存在不完全反应;燃料Mg的消耗主要通过与CF₂的氧化反应,Mg与F的反应过程不能忽略,且随着质量比的增大,燃烧产物MgF的比例减少。     

固冲发动机补燃室内硼颗粒点火和燃烧数值研究

采用颗粒轨道模型进行了含硼贫氧推进剂固体火箭冲压发动机补燃室两相流的数值模拟,其中硼颗粒的点火和燃烧模型采用的是King模型,建立了发动机补燃室内简单反应流模型,并在该模型下对某实验发动机进行了模拟,得出颗粒在补燃室内的分布,结果表明:进入头部回流区的硼颗粒能够快速点火,并且颗粒直径增大后,点火时间增加,颗粒燃烧效率显著降低.     

燃烧轻气炮氢氧燃烧特性详细反应动力学模拟

应用氢氧燃烧19步详细化学反应机理,建立了某燃烧轻气炮氢氧燃烧单区模型,数值模拟了氢氧混合气体燃烧发射弹丸的过程。模拟结果与文献［1］实验结果基本吻合,较好地模拟了某燃烧轻气炮氢氧燃烧热力学过程。在此基础上,对多种工况参数下的氢氧混合气体燃烧进行了系统仿真计算,分别讨论了初始温度、初始压力、稀释气体成分与比例对燃烧轻气炮氢氧燃烧特性以及内弹道性能的影响,分析了氢氧燃烧过程中各化学组分的变化。研究结果表明,氢氧混合气体初始温度、初始压力和稀释气体成分与比例对燃烧轻气炮内弹道性能有着显著影响。     

纳米铝粉在环氧丙烷快速反应中的热学行为研究

研究了入射激波作用下平均粒径75 nm左右纳米铝粉与环氧丙烷快速反应中的热学特征.用光谱技术测定入射激波作用下纳米铝粉在环氧丙烷快速反应的点火延迟时间约为8 μs; 利用标定的ICCD光学系统采集到的AlO(B2Σ -X2Σ )光谱数据,计算纳米铝粉反应温度约为3189 K.对反应生成物的形貌特征进行了研究,测试结果表明: 反应产物多为球状颗粒,部分为絮状和针状,其平均粒径约为70 nm,小于反应前纳米铝粉的平均粒径,粒径明显减小是烧结塌陷致密所致;少部分产物粒径大于100 nm, 粒径增大是反应物凝聚所致.     

金属燃料在不同气氛中的点火温度

利用自行设计的金属燃料点火温度测试系统,测试了常压下分别在空气和氧气中的镁包覆硼粉（包覆度20%）、镁粉及铝合金am-Al的点火温度。结果表明,与在空气中相比,3种金属燃料在氧气中的点火温度均有所降低;镁包覆硼粉有效降低了硼的燃点,促进了硼的点火和燃烧,且镁包覆硼粉在氧气中更易燃烧,其点火温度仅为约195.92℃;am-Al在氧气中可点燃,其点火温度低于镁,且燃烧放出的热量最高。在充足的氧气环境下,镁包覆硼粉及am-Al的点火温度均低于300℃,二者均可用作高热值金属燃料。     

固液混合火箭发动机简单反应流模拟

建立了基于阿累尼乌斯公式和粘性流体力学的混合发动机（HRM）简单反应流模型，并在该模型下对某实验发动机进行了模拟，得出了反应物和产物组分、燃速、温度等发动机参数的变化趋势，给出了一些有用的结论，论证了该反应流模型的准确性。     

高密实含能颗粒床燃烧转爆轰的实验与理论研究

给出了高密实含能颗粒床燃烧转爆轰现象的实验研究结果。根据实验观察到的现象，建立了描述燃烧转爆轰的两相流数学物理模型，并对模型中的某些本构关系作了改进。用MacCormack差分格式和自适应网格技术，对伴有强冲击波形成的物理过程进行了数值求解。数值预测的火焰传播、诱导爆轰长度和稳态爆轰速度与实验结果基本吻合，其结果与作者已发表的燃烧转爆轰的机理分析相一致[1]。     

铝颗粒氧化机理与燃烧理论研究进展

为对固体推进剂中铝颗粒的点火和燃烧反应提供一定的理论指导,详细介绍铝颗粒的氧化机理和燃烧理论。阐述铝颗粒的两种氧化反应机理:扩散氧化机理和熔散氧化机理,指出不同实验条件导致点火温度差距较大的原因。并通过回顾铝颗粒燃烧模型的发展历程,详细介绍半经验模型、化学机理模型和CFD模型的发展。提出未来铝颗粒氧化机理及燃烧的研究方向为复杂氧化气氛下(CO_2和H_2O)的氧化机理及模型研究、促使铝颗粒发生熔散反应的研究、铝颗粒燃烧的CFD模型研究。     

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.     

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.     

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.     

Overview of Anti-tank Mines

First the different anti-tank mines laying possibilities are shortly summarized： hand emplaced, with mine layers, ground or helicopter relatively topographical well defined, and with cluster systems of projectiles, rockets and aircraft dispensers. Then examples of the three generations of anti-tank mines are presented：Ⅰ generation： detonating only beneath the track; Ⅱ generation： detonating beneath the track and belly; Ⅲ generation： mines with off-route actions. Weight and cost comparisons are strongly favoring the off-route Ⅲ-generation mines.     

A Finite Element Analysis on Static Strength of a Complex Section

A static finite element analysis （FEA） of an impulsive controller section is presented. The boundary condition and a part of the loads are applied. Considering the grades of the stress around the holes being large, the dense grids are adjusted accordingly. Four cases with different loads are compared, thus the influences of different loads on the section are analyzed. Numerical results show that the maximum stress of the section is lower than the strength limit of the material, and the section will not be broken with the static loads.     

Discussion on Mechanism of Breech-Blow Caused by Propellant Charge

From the view point of launch safety caused by fracture of propellant charge, this paper points out that the safety criterion of pressure wave is inadequate to evaluate the launch safety of propellant charge based on the initial negative differential pressure and sensitivity tests. Generally, the maximum barrel pressure does not depend upon the intensity of pressure wave correspondingly. The pressure wave intensity can not describe the fracture degree of propellant charge in chamber and reflect the mechanical environment of propellant charge fracturing exactly and wholly. The evaluation criterion for launch safety of propellant charge should be built on the basis of depicting the fracture degree of propellant bed.     

Experimental Studies of Toxicity on HNIW and Its Intermediates

The polycyclic nitramine hexanitrohexaazaisowurtane（HNIW） is a compound of high energy density. HNIW can replace 1, 3, 5-trinitro-1, 3, 5-triazacyclohexane（RDX） or HMX, hut its toxicity is unknown. In this paper, HNIW, hexabenzylhexaazaisowurtzitane （HBIW）, tetraacetyldibenzulhexaazaisowurtzitane （TADBIW）, tetraacetyldiformylhexaazaisowurtzitane（TADFIW） and tetraacetylhexaazaisowurtzitane（TAIW）, which are intermediates of the synthesis of the HNIW, were selected as the tested objects in acute toxicity test, acute eye stimulation test and skin irritation test according to the standards of ＂chemical product testing method-401 ： acute oral toxicity test＂, ＂chemical product testing means-405： acute eye irritation/corrosion test＂ and ＂chemical product testing means-404： acute dermal irritation/corrosion test＂ of National Circumstance Protect Bureau. The results show that all of the five objects have no toxicity, no stimulation to eye and skin under the tested conditions.     

Dynamic Simulation for Missile Erection System

In order to study the dynamic characteristics of the missile erection system, it can be considered as a rigid-flexible coupling multi-body system. Firstly, the actual system is abstracted as an equal and simplified one and then the forces applied to it are analyzed. Secondly, the rigid-flexible coupling dynamic simulation for erection system is accomplished by use of the system simulation software, for example Pro/E, ADAMS, ANSYS, MATLAB/Simulink, etc. Finally, having the aid of simulation results, the kinetic and dynamic characteristics of the flexible bodies in erection system are analyzed.The simulation considering the erection system as a rigid-flexible coupling system can provide valuable results to the research of its kinetic, dynamic and vibrational characteristics.