某伺服系统超高速涡轮泵轴系预紧螺纹联接失效分析

针对某伺服系统超高速涡轮泵的重要部件--轴系预紧螺纹联接,进行了失效分析,采用第四强度理论对涡轮泵轴系螺纹联接进行了强度校核.在此基础上,结合试验验证与失效结果对比,分析了涡轮泵装配过程中拧紧力矩以及涡轮泵工作过程中附加最大动载荷对螺纹失效的影响规律,为后续的加工精度分析和系统可靠性提供了理论依据.     

LE—7发动机液氢涡轮泵研制中的问题

日本ＬＥ－７发动机的液氢涡轮泵在研制过程中多次出现问题，经对涡轮叶片、叶轮、导流叶片、轴系做了大量修改和试验后得到解决。     

LE－7发动机液氢涡轮泵研制中的问题

日本ＬＥ－７发动机的液氢涡轮泵在研制过程中多次出现问题，经对涡轮叶片、叶轮、导流叶片、轴系做了大量修改和试验后得到解决。     

航天飞机主发动机高压涡轮泵工作寿命的改进

当前航天飞机主发动机第一阶段发动机已经验证在高达104％额定功率下具有极好的飞行性能。早期在109％额定功率下作的鉴定试验表明,高压涡轮泵的工作寿命受到一定限制。第二阶段发动机研制计划自1983年以来一直在进行着,旨在提高工作寿命并提供附加余量。本文中介绍了航天飞机主发动机第一阶段发动机的研制历史和第二阶段发动机的设计和结果,以及高压涡轮泵工作寿命极限及其需大量维护的关键部件的验证情况,并概述了第二阶段发动机的设计改进、基本分析和试验结果。此外,在本文中还讨论了正式的鉴定试验计划。高压燃料涡轮泵已作了改进,以便减低涡轮工作温度,延长一、二级涡轮叶片的工作寿命并减小金属板维护工作量。高压氧化剂涡轮泵也作了改进,以便改进轴承工作寿命并消除次同步旋转问題。对于这些改进以及为了快速评估其优点而设计和使用的专用仪表都作了详细讨论。     

一种超高速特斯拉涡轮式煤油发电机的研究

超高速特斯拉涡轮式煤油发电机(以下简称"发电机"),利用引流火箭发动机的高压煤油,将其作用于特斯拉涡轮叶片的流体剪切力转化为向外输出的旋转机械能,驱动发电机同步旋转进行发电.运用CFX流场仿真软件对其流场进行了仿真计算,得出特斯拉涡轮转子流域压力分布云图及速度矢量云图、输出功率、扭矩等参数.运用Ansoft软件对发电机...     

航空涡轮叶片叶身造型参数化设计

为提高航空涡轮叶片设计的数字化水平,减轻设计人员的设计计算量,开发了一种基于CATIA的航空涡轮叶片建模方法。首先在分析涡轮叶片几何特征及其气动性能和结构强度的影响因素,确定了叶片截面形状的控制参数,再运用内建于CATIA的知识工程工具和函数,构造三维涡轮叶片。该方法实现了涡轮叶片设计的参数化,所设计叶片的叶身曲面和不同径向位置的截面曲线均达到G2连续。     

航天飞机主发动机涡轮叶片单晶超导合金的研究

本文研讨了航天飞机主发动机涡轮叶片单晶超导合金的性能。试验了样品在常温和高温条件下的抗拉强度。给出了柔度系数和动力弹性模数与温度之间的关系曲线。计算了航天飞机主发动机涡轮叶片的振动性能。     

超高速涡轮泵机械密封工作特性分析

超高速涡轮泵机械动密封需满足可靠性及寿命指标要求,在研制阶段,需通过理论分析研究机械密封工作特性。在对机械密封动力稳定性与密封端面磨损换热特性分析研究的基础上,针对所选用的机械密封形式,选取合适的参数,校核机械密封相关性能参数,并对密封副工作特性进行初步研究,得到密封副泄漏量的变化规律、动力稳定性及其端面散热量,以确定合适的冷却液流量。该机械密封工作特性分析的应用为超高速涡轮泵的寿命与可靠性试验验证提供了一个合理的、高效费比的技术途径。     

绝热涡轮复合发动机动力涡轮的设计与试验

本文叙述了用于绝热涡轮复合发动机的动力涡轮的设计与试验,给出了动力涡轮的气动、热力计算结果。试验得出了动力涡轮的特性曲线,其流量和效率均与设计值相符,表明设计是成功的。     

某型弹用发动机高压涡轮叶片断裂故障模式影响分析

针对某型弹用发动机试样研制阶段的地面、飞行试验各阶段中可能发生的各种故障模式、发生故障的原因及其对发动机工作过程和飞行试验的影响进行分析,列出该型发动机试样研制阶段的FMEA表.对发动机高压涡轮叶片可能潜在的断裂故障模式做出FMEA分析.同时基于发动机残骸分解检查、高压涡轮转子叶片断口分析、发动机性能计算、控制系统工作分析、发动机工作寿命分析,对故障发生的原因和机理进行研究,形成飞行试验中某发动机高压涡轮叶片断裂故障发生的原因及结论.     

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.     

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.     

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.     

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.