固体燃料冲压发动机燃烧室内流场数值模拟

为研究突扩台阶高度、尺寸缩放及燃料长度对固体燃料冲压发动机燃面退移速率及火焰稳定性能的影响,以聚乙烯为燃料,对固体燃料冲压发动机燃烧室内流场进行了数值模拟研究。结果表明:随着突扩台阶高度的不断增大,燃料通道内的湍流动能逐渐增大,燃料的燃面退移速率、补燃室温度及压力逐渐增大;在保证空气质量通量及总温相同、几何相似的条件下,随着尺寸的不断减小,燃料壁面附近的温度梯度及有效导热系数不断增大,使燃料的燃面退移速率逐渐增大,富氧程度降低,补燃室压力增大,回流区内燃料汽化的吸热速率占该区域内化学反应的总放热速率的比例不断升高,发动机火焰稳定性能降低;在保证其他参数相同时,在增大燃料长度,同时不改变燃料通道内相同轴向位置处的流场温度、燃料燃面退移速率及组分分布的情况下,燃料长度越长,固体燃料的平均燃面退移速率越小,补燃室温度及压力越高。     

高固体含量丁羟推进剂性能研究

为进一步提高HTPB推进剂的能量水平,从理论和实验两个方面研究了固体组分含量对HTPB推进剂的能量性能、燃烧性能和力学性能的影响。结果表明,随固体含量的增加,推进剂理论比冲增加,当固体含量为90%(高氯酸铵37%、黑索今36.6%、铝粉17.4%)时,其理论比冲可达270.62s;高氯酸铵43%、黑索今30%、铝粉17%时,燃速压力指数约为0.34,-40℃时的最大延伸率为48%。当固体含量为88%(高氯酸铵48%、黑索今23%、铝粉17%)时,调节HTPB推进剂配方填料粒度及级配,燃速可从7.0MPa下的7.0mm·s-1提高至10.9mm·s-1,燃速压力指数相当(约为0.4),20℃时的最大延伸率可达74%。     

石蜡燃料的燃烧性能与其化学组成的关系

为了研究石蜡的燃烧性能与其化学组成之间的关系,针对54~#、58~#、62~#和66~#4种粗晶石蜡开展了气相色谱分析,并测试了4种石蜡的燃烧热和在氧气流中的瞬时退移速率,同时利用N ASA-C EA软件计算了4种石蜡燃料不同氧燃比下的能量特性。结果表明:54~#、58~#、62~#和66~#4种粗晶石蜡的平均分子式分别为C_(26.40)H_(54.80)、C_(27.59)H_(57.18)、C_(28.02)H_(58.04)和C_(32.11)H_(66.22),正构烷烃含量分别为92.79%、89.44%、88.36%和84.55%;平均碳数n越大、正构烷烃含量越小的石蜡其燃烧热越低;随着平均碳数n值的增大以及正构烷烃含量的降低,石蜡的退移速率降低。NASA-CEA程序计算得到4种石蜡的能量特性受其化学组成的影响很小,其最佳氧燃比均为2.7,对应的理论比冲约为354 s,绝热火焰温度约为3600 K。     

基于AP预处理技术的粉末推进剂性能

为了提高高氯酸铵(AP)粉末推进剂的长期贮存性和高效燃烧性,利用预处理技术对AP粉末进行包覆团聚,改善其表面特性。采用吉布斯最小自由能法计算Al/AP粉末火箭发动机的能量特性,利用预处理实验分析端羟基聚丁二烯(HTPB)对AP粉末的装填密度、吸湿性能和热分解特性的影响,并进行密闭燃烧器点火实验,研究氧燃比和装填量对Al/AP粉末推进剂能量特性参数的影响规律。结果表明:AP的最佳预处理材料配比为添加10%HTPB,且在氧燃比为3∶1时,Al/AP粉末火箭发动机的理论比冲最高达262.1s;一定范围内,随着氧燃比的增加,粉末推进剂的能量特性参数均有所增加;在氧燃比相同条件下,单位质量粉末推进剂成气量基本相同,随着粉末装填量的增加,燃温和特征速度均有所提高。     

氧化高氮杂环羟胺盐在固体推进剂中的能量性能分析

为评价新的氧化高氮杂环羟铵盐作为复合固体推进剂组分的能量潜力,采用推进剂性能评估程序PEP模拟计算了3,3'-二硝基-5,5'-联-(1-氧-1,2,4-三唑)二羟铵(DHDNBT)、5,5'-联-1,1'-二氧-四唑二羟铵(TKX-50)和5,5'-偶氮联-(1-氧四唑)二羟铵(DHABT)取代AP/Al/HTPB和AP/Al/GAP+NE两种复合固体推进剂体系中AP后的能量效果,并与HMX进行了比较。结果显示,在高固体含量的AP/Al/HTPB体系中,TKX-50和DHABT取代部分AP所得到的配方在很大的配方调节范围内能量性能与HMX取代AP配方相当,DHDNBT取代AP所得配方能量特性与同样含量HMX取代AP所得配方相当。在AP/Al/GAP+NE体系中,DHDNBT配方能量性能与同样含量HMX配方相同。含TKX-50和DHABT配方能量性能优于含HMX配方。含TKX-50和DHABT配方最高冻结流比冲分别为2662.7 N·s·kg-1和2696.0 N·s·kg-1,比HMX取代同体系中AP所得配方的最高冻结流比冲(2622.5N·s·kg-1)高40.2 N·s·kg-1(TKX-50)和73.5 N·s·kg-1(DHABT)。用设想的双-(1-氧-四唑)胺二羟铵(DHBTA)取代AP/Al/GAP+NE体系中AP可使最高冻结流比冲达到2708.7 N·s·kg-1,比HMX取代同体系中AP所得的最高冻结流比冲高86.2 N·s·kg-1,且在很大配方调节范围内有比HMX配方更高的能量特性。     

高剪切速率下硼与HTPB、PBT和GAP端羟基的反应活性

含硼富燃料推进剂具有较高的质量热值和体积热值,是固体火箭冲压发动机较理想的燃料之一,而无定形硼与黏合剂中的羟基可发生反应,导致推进剂药浆表观黏度增大快、药浆适用期缩短等问题。计算了分别以端羟基聚丁二烯(HTPB)、3,3?二叠氮甲基氧丁环?四氢呋喃共聚醚(PBT)和聚叠氮缩水甘油醚(GAP)为粘合剂的含硼推进剂的理论体积热值,并采用双螺杆转矩流变仪和红外光谱研究了B/HTPB、B/PBT和B/GAP体系在高剪切速率混合过程中的流变和红外特性,分析了硼粉表面酸性杂质与粘合剂端羟基的反应活性。结果表明,经过合理配方设计,B/PBT/AP和B/GAP/AP的质量比为50∶20∶30时的体积热值均超过64.00 MJ·~(-3),大于B/HTPB/AP体系的体积热值(61.08 MJ·dm~(-3))。在剪切速率为355.56 s~(-1)、55℃条件下,含25%硼的B/HTPB体系表观黏度快速增加到260 Pa·s,混合110 min发生凝胶现象;含40%硼的B/PBT体系混合7 h黏度仅从3.63 Pa·s上升到10 Pa·s;含55%硼的B/GAP体系混合7 h黏度由5.96 Pa·s下降到0.33 Pa·s。B/HTPB混合体系红外光谱B—O振动吸收峰随着混合时间的增加而逐渐增强,C—O(伯醇)振动吸收峰随着混合时间的增加而逐渐减弱,而B/PBT和B/GAP体系混合420 min后红外光谱B—O振动吸收峰和C—O(伯醇、仲醇)振动吸收峰几乎没有变化。PBT和GAP端羟基与硼粉酸性杂质的反应活性比HTPB的端羟基的活性低很多,这有利于改善含硼推进剂药浆的工艺性能。     

含RDX的硝胺丁羟推进剂能量特性研究

采用最小自由能平衡流法对RDX/AP/Al/HTPB推进剂能量特性进行了理论计算。通过BSF165mm和BSF315mm发动机点火试验,研究了RDX含量、燃烧室压强对RDX/AP/Al/HTPB推进剂能量特性的影响规律。根据理论计算和发动机试验结果,对配方进行了优化设计,与某型号760mm全尺寸发动机的实测结果对比,其实测比冲高达2428.1N·s·kg-1(pc=6.86MPa),验证了RDX的加入对RDX/AP/Al/HTPB推进剂比冲有较突出贡献。     

AP/HTPB复合固体推进剂慢烤燃特性的数值模拟

为了研究热载荷作用下高氯酸铵(AP)/端羟基聚丁二烯(HTPB)推进剂的热安全性,针对某固体火箭发动机建立了二维烤燃简化模型。其中,AP/HTPB推进剂的慢烤燃过程采用两步总包反应描述。理论计算结果与实验数据吻合较好。在此基础上,分别对该发动机在升温速率为1.8,3.6,7.2 K·h-1下的慢速烤燃行为进行了数值预测。结果表明,三种升温速率下,AP/HTPB推进剂的最初着火位置均发生在药柱内壁纵向1 mm肉厚的环形区域内,且随着升温速率的增大,最初着火位置由中心区向药柱壳体端面移动。升温速率从1.8 K·h-1增加到7.2 K·h-1时,着火温度从592 K升到595 K,变化不大,但是着火延迟期却从31.48 h缩短到14.87 h。     

石蜡/HTPB燃料的力学性能

为了研究端羟基聚丁二烯(HTPB)体系质量分数以及温度对石蜡/HTPB燃料力学性能的影响,制备了7种不同配方石蜡/HTPB拉伸试件,并使用万能材料试验机以10 mm·min~(-1)拉伸速率进行了单轴拉伸实验,分析了燃料的最大抗拉强度、断裂伸长率和初始弹性模量变化规律。结果表明,随着HTPB体系质量分数增加,燃料的断裂伸长率增大,而最大抗拉强度和初始弹性模量皆减小;当环境温度较高(接近石蜡熔点58℃)时,燃料的最大抗拉强度和初始弹性模量皆随着HTPB质量分数增加而增大;燃料的最大抗拉强度随温度降低而逐渐增大,其中当温度由20℃降低至-40℃时,H20燃料最大抗拉强度由1.189 MPa升高至2.150 MPa;以HTPB体系为基体、石蜡为填料的石蜡/HTPB燃料,在其基体与填料的界面上存在相互阻滞作用力,可提高燃料的力学性能。     

纳米镍粉对改性双基推进剂综合性能的影响

为了研究纳米镍粉(nano-Ni)对含铝改性双基(Al-CMDB)推进剂以及含黑索今和铝粉的改性双基(RDX/Al-CMDB)推进剂综合性能的影响,采用吸收-沟槽压延-螺旋压伸法制备了推进剂药柱,测试了nano-Ni对推进剂热安定性能、机械感度、力学性能、能量性能、发动机内弹道性能、室温条件下长贮燃速变化的影响。结果表明,nano-Ni对Al-CMDB推进剂和RDX/Al-CMDB推进剂的热安定性能、机械感度、力学性能、能量性能、长贮条件下燃速变化影响不明显。但是nano-Ni可显著改善Al-CMDB推进剂和RDX/Al-CMDB推进剂的燃烧性能。nano-Ni使Al-CMDB推进剂9.81 MPa燃速从28.32 mm·s~(-1)增加到35.94 mm·s~(-1),12～22 MPa的压强指数从0.26降低至0.12,nano-Ni使RDX/Al-CMDB推进剂9.81 MPa燃速达到36.63 mm·s~(-1),16～22 MPa高低常温均出现负压强指数,Φ130 mm发动机-40℃比冲达到241.1 s,50℃比冲达到246.9 s。     

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.     

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.     

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.     

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.     

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。     

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.     

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.     

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.