新一代运载火箭时序仿真系统信号完整性分析

新一代运载火箭时序仿真系统具有数字电路速度快、集成度高的特点,系统要求发出多路高精度时序、时串信号以满足新一代运载火箭地面测试设备的检查与校准需求,因此信号完整性问题在系统设计中不容忽视。针对仿真系统的典型模块(USB 3.0 Super-speed差分线、FPGA外设数据走线、时钟走线)进行建模分析仿真得出PCB硬件电路设计参数,给出时序仿真系统设计信号完整性问题的抑制和解决方法,优化了板级信号质量,改善系统可靠性、工作连续性和输出精度,可有效提高新一代运载火箭测试效率和测试可靠性。     

水下武器发射时流噪声研究

水下鱼雷武器发射噪声是潜艇的特殊噪声源。为直观详尽地描述发射系统内鱼雷出管的具体情况,本文建立了潜艇水下鱼雷安静发射普遍采用的液压平衡式发射装置内部及外部流场的有限元分析模型。基于FLUENT的动网格技术进行数值模拟,计算分析了发射过程的速度场和压力场,以及由此引起的发射流噪声特性。探讨了发射速度、发射管内外压力、潜艇航速或外部流场、水深等多种因素对鱼雷水下发射噪声的影响。     

Active sloshing control in a smart flexible cylindrical floating roof tank

An exact three dimensional fully-coupled hydro-elastic analysis for transient liquid sloshing in a partially-filled vertically-standing flexible circular cylindrical shell container fitted with a freely floating smart piezo-sandwich thin elastic circular plate is presented. The problem formulation is based on the linear water wave theory, the classical (Kirchhoff/Sanders) thin plate and shell models, Maxwell's equations of electrodynamics, Stokes’ transformation, and eigen-function expansions in cylindrical coordinates. The control action is achieved by combined volume displacement and volume velocity feedbacks (VDF, VVF) implemented in a second order active damping (AD) compensator via two competent evolutionary heuristic optimization techniques that systematically tune the controller gain parameters while constraining the floating panel displacement and control voltage. The uncontrolled and controlled transient responses of the coupled hydro-elastic system under various external disturbances (i.e., a harmonic base excitation, a real seismic event, a severe launch vehicle liftoff event, and a distributed impulsive transverse load on the floating panel) are calculated by means of Durbin's numerical inverse Laplace transform scheme. Moreover, the free vibration characteristics of the coupled fluid/structure interaction (FSI) system are briefly studied. The superior performance of the proposed active floating roof control configuration in effective suppression of the key hydro-elastic parameters (panel displacement, and shell displacements/stresses) is demonstrated. It is also found that, in the current FSI control problem, the Multi-objective Particle Swarm Optimization (MOPSO)-based ADC outperforms the Non-dominated Sorting Genetic Algorithm (NSGA-II)-based method, in terms of convergence rate and computational effort. Limiting cases are examined and the precision of results is verified by comparisons with the existing data as well as with the results produced by a commercial finite element package.     

"长征五号"独白

Through the self-introduction of the Long March 5 carrier rocket, this paper vividly presents the chemical mystery of the important parts of the carrier rocket, thus providing readers with the charm of chemistry in a relaxing manner.     

Numerical implementation and applications of a coupling algorithm for structural–acoustic models with unequal discretization and partially interfacing surfaces

The numerical implementation of a coupled finite element–boundary element algorithm for computing simultaneously the structural vibration and the associated acoustic field and a complete set of validation and application data is presented. The new developments in the coupling algorithm presented in this paper are associated with a capability for unequal mesh density between the structural and the acoustic model, division of both models into interfacing and non-interfacing zones, efficient computation of the coupling matrices, and incorporation of acoustic multiple connection constraints in the coupling computations. Applications are identified in the area of launch vehicle dynamics where a reverberant acoustic environment provides the excitation for computing either noise transmitted through flexible structures, or noise-induced vibration due to acoustic loads. Results and correlation to test data are presented for a fairing and an expansion nozzle of a rocket. Numerical results are also compared to an analytical solution for noise transmitted through a flexible cavity backed plate.     

高温超导磁悬浮冷发射装置供电控制系统的设计

介绍了一种基于单片机控制的供电控制系统,系统以ATMEL89C52为核心,以高温超导磁悬浮冷发射装置驱动系统为控制对象,实现了驱动装置的分段供电,实时检测到发射载体的运动速度,减小了供电系统的负荷,提高了驱动装置的运行效率。     

Applied Mechanics Problems Accompanying Spacecraft Launches from a Floating Platform and Their Resolution by the Sea Launch Project

The technologies applied by SDO Yuzhnoye to implement the Sea Launch Project are exemplified to describe the recent achievements in designing space launch vehicles. Consideration is given to the loads acting on launch vehicles during long-term sea transportation and prelaunch operations in rough sea. Experimental methods for determining those loads are described, and techniques for reducing them are proposed. Presentation is also given to methods of providing launch safety under conditions of limited space for launch-support equipment and reducing the thermal and vibroacoustic loads on the launcher. The efficiency of the methods described is confirmed by the success of the Sea Launch Project     

基于国产网络设备的火箭地面测发控网络平台设计

高可靠的测试网络作为运载火箭远距离测发控的基础平台,是实现运载火箭地面远距离测试发控的重要技术保障。通过对运载火箭地面测发控网络架构深入研究,采用国产商用网络设备搭建原型平台、开展原理性验证试验,经过反复试验,不断改进技术方案,解决了冗余热备网络协议选用、冗余故障切换、故障切换实时性、网络可靠性等技术难题,提出了基于国产化设备的网络架构设计方案。对网络架构的工作原理、可靠性、实时性、安全性进行了详细分析。建立的国产化高可靠网络架构,不仅能够应对复杂的火箭测试现场,使网络平台具有更好的可靠性、实时性、扩展性和灵活性,更进一步提高了网络的安全性。设计的国产化网络平台架构可用于运载火箭地面测发控网络使用。