网格生成方法在APFSDS及弹托干扰流场计算中的应用

介绍APFSDS及弹托干扰流场数值模拟中的网格生成方法及其应用。利用等比数列网格生成技术，三维弧长生成技术以及拼接技术生成计算网格。该方法具有简明、快捷的特点。在临近物面的地方具有较好的贴体性和正交性。在计算脱壳穿甲弹和弹托之间的干扰时，将弹托简化为带圆弧的楔形块，计算结果比较令人满意。     

自适应方法在APFSDS干扰流场模拟中的应用

对常用的网格自适应方法进行总结分析,指出它们的不足,在此基础上,采用基于网格局部重构的网格自适应方法对网格进行自适应,用Delaunay方法生成三维非结构网格,并对生成的网格进行了优化.以基于格心的有限体积法为基础,空间二阶精度,采用LU-SGS隐式方法求解Euler方程,网格单元边界处守恒量通量的计算采用了Hanel方法,对NACA0012翼型绕流及脱壳穿甲弹弹托分离流场进行了数值模拟,取得了较好的结果.     

弧长参数生成法及其在冲压加速器中的应用

该文根据冲压加速器边界形状复杂的特点，利用贴体网格的弧长参数生成法，将计算域分块生成网格，而后拼接起来。用三次插值函数控制边界的网格点疏密分布，利用新方法将子块光滑拼接，为进一步研究冲压加速器的流场奠定了基础。     

基于动网格CFD技术的膛口弹前激波流场数值模拟

针对数值模拟弹丸膛内加速运动造成的网格变化,采用分块网格划分的整体运动处理方法和基于动态层变方法的结构动网格技术,保证了数值网格的质量。模拟弹丸膛内运动的弹前激波流场,并描述了激波流场的形成,发展过程,实现了含运动弹丸的膛口激波流场模拟。数值计算结果与实验照片进行对比,弹前激波流场的形状和位置能较好吻合,表明数值模拟方法是合理可行的。     

弧长参数生成法及其在冲压加器中的应用

该文根据冲压加速器边界形状复杂的特点，利用贴体网格的弧长参数生成法，将计算域分块生成网格，而后拼接起来，用三次插值函数控制边界的网格点疏密分布，利用新方法将子块光滑拼接，为进一步研究冲压加速器的流场奠定了基础。     

基于结构重叠网格的栅格翼导弹流场数值仿真

采用结构重叠网格方法对栅格翼导弹的粘性流场进行了数值仿真计算,相对于单一结构网格而言,该方法不但降低了网格生成难度,提高了网格质量,而且大幅度降低了网格数量,计算结果表明该方法是可靠有效的。     

动态网格在固体火箭发动机内流场计算中的应用研究

固体火箭发动机在工作过程中内流场结构随燃面的减退不断发生变化，利用通常的稳态网格难以对该问题进行准确模拟。针对此问题，首先介绍了实现动态网格的基本方法，然后采用动态层方法生成动态网格对某固体火箭发动机内流场进行了计算。计算结果与实验数据的对比说明使用动态网格方法计算的准确性和可行性，与准稳态方法计算结果的比较说明在时间步长较大以及流场参数变化剧烈的情况下，动态网格方法更适用于火箭发动机内流场的计算。     

表面润湿性对球体入水空泡形态的影响研究

基于Navier-Stokes方程,采用流体体积法多相流模型,并引入动网格技术,对不同表面润湿性球体的垂直入水问题开展了数值模拟研究。将球体垂直入水空泡形态的数值结果与实验结果进行对比,验证了数值结果的正确性。对不同润湿性球体的垂直入水空泡形态的研究结果表明,球体入水空泡形态主要有4种：完全无空泡、深闭合空泡、面闭合空泡以及类面闭合空泡。入水初期形成的液体薄层是影响随后产生空泡形态的关键因素。进一步分析表明,生成不同空泡形态的临界速度与球体的表面润湿性有密切关系,建立了描述入水空泡生成的临界速度与表面接触角关系的经验公式。     

三维直角网格自适应DSMC数值模拟

利用物面网格和流场网格耦合处理的方法,编制了三维再入飞行器稀薄高超声速绕流流场通用的DSMC计算程序,发展了一种高效、小存贮自适应多级直角网格技术,计算了圆球自由分子绕流和稀薄过渡区球双锥体绕流流场结构特征和气动力热特性,并将圆球自由分子绕流的计算结果、理论解以及超热力学解进行了了比较,利用直角网格自适应技术模拟了头双锥外形再入飞行器流场结构和气动力系数,验证了流场网格和物面网格处理方案和计算程序的可靠性.     

弹丸绕流流场贴体网格自动生成研究

贴体曲线网格的自动生成是弹丸绕流流场数值模拟技术的重要组成部分.本文采用Thompson任意曲线网格生成方法和非齐次离散源项,研究了弹丸流场求解域的网格生成问题.实际的流场计算表明,用这种方法生成的曲线网格,完全满足弹丸绕流流场Navier-Stokes方程数值模拟的需要.     

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.     

Expert Systems Aimed at General Design of Projectiles

Expert systems aimed at the general design of projectiles can implement a series of intelligent designs, such as the design of HE shell, the scheme expounded and proved, the emulation analysis and calculation, etc. Aiming at the product design feature, the expert system adopts the object-oriented knowledge representation and all kinds of inference control engines to describe and reason the relevant knowledge regarding the product through the microcomputer. It embodies the foundation of emulation analysis and simulated manufacturing of the shell. It makes use of the method that knowledge expression is combined with condition of inference to carry out the overall design and emulation and reference.The paper gives the ways through which the functions can be achieved, gives the modularization of reference and the design methods of systematization, puts forward the method of knowledge expression and working interface, and supplies a platform for similar products of the shell category that can be quickly designed.     

Parameter Identification for the Valve Control Cylinder System of a Hydraulic Manipulator

In mechanical, hydraulic and electronic systems, the determination of system parameters is often challenging because liquid parameters often change significantly, due to variations in working and environmental conditions. Therefore, it is of significant practical importance to identify those parameters through experimental procedures. A systematic approach to identifying parameters in the valve controlling cylinder system of hydraulic manipulators is provided. It first derives the transfer function of the system, and then uses P control of PID control to predict system parameters. The predicted parameters are further validated using PID control. The prediction through simulation using MatLab language is utilized, which agrees well with experimental results.     

Three-dimensional Numerical Simulation of Combustion Field in the Combustion Chamber

In order to study the effect of rotation on the combustion in the underwater vehicle, a two-phase turbulent combustion process is described with Reynolds stress turbulence model, eddy-dissipation turbulent combustion model, P-1 radiation model and particle tracking model of liquid. The flow in the rotating combustion chamber is simulated at two different working speeds, 0 r/min and 1 000 r/min by Fluent software. The temperature, gas velocity, static pressure of wall and fuel concentration are computed and compared. The results show that the combustion in rotating combustor is faster and more effective.     

Software Communication Architecture Implementation and Its Waveform Application

This paper attempts to do a research on the development of software defined radio（SDR） based on software communication architecture（SCA）. Firstly, SCA is studied and a whole reference model of SCA3.0 core framework （CF） is realized; Secondly, an application-specific FM3TR waveform is implemented on the platform of common software based on the reference model; Thirdly, from the point of view of real-time performance and software reuse, tests and validations are made on the above realized CF reference model and FM3TR waveform. As a result, the SCA-compliant SDR has favorable interoperability and software portability and can satisfy the real-time performance requirements which are not too rigorous.     

Dynamic Simulation of the Tank Gun Recoil Response

By using the ATV module of MSC. ADAMS, the dynamic simulation of recoil response of tank gun is analyzed.How the recoil force affects the bodywork and the suspension during gun firing, as well as the changing status of the gun muzzle‘s velocity are gained. All results and analyzing methods are offered for the designing basis of optimizing tank vehicle-gun match. The constructive exploration is beneficial to improving the general capability of tank.     

Survey of Controllable Suspension System for Off-road Vehicles

The controllable suspension system can improve the performances of off-road vehicles both on road and cross-country. So far, four controllable suspensions, that is, body height control, active, semi-active and slow-active suspensions, have been developed. For off-road vehicles, the slow-active suspension and the semi-active suspension which have controllable stiffness, damping and body height are more appropriate to use. For many years, some control methodologies for controllable suspension systems have been developed along with the development of modern control theory, and two or more original control methods are integrated as a new control method. Today, for military or civilian off-road vehicles, the R&D of controllable suspension systems is ongoing.     

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.     

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.     

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.