Influence of the gas-distributing grid structural features on the flow parameters in the liquid-propellent rocket engine with producer gas afterburning

The analysis of structural features of the gas-distributing grid was carried out by modern facilities of computational gas dynamics to equalize flow parameters upstream of a mixing head in LPRE with producer gas afterburning. For the given simulation conditions we defined the optimal geometrical dimensions of the facets on the gas-distributing grid openings, providing the maximal discharge coefficient and the minimal pressure differential. We also examined the grid design variants with the various distribution of facets of different geometry, which allows the outflow parameters to be varied according to the grid area. It is obtained, that a flat grid with various openings geometry in the sectors makes it possible to provide the best equalization of the pressure and velocity fields upstream of the mixing head and the minimal pressure losses.     

Nonlinear dynamics of antennas in space communication facilities

A mathematical model of complex vibrations for the cantilever Bernoulli-Euler beam in the XOZ plane constructed by the finite difference and finite element methods and the fourth-order Runge-Kutta method is presented. We determined the critical value of the damping coefficient ɛ = 0.28, at which the system changes from the dissipative state to conservative one, using the Morlet wavelet. The results of analyzing the frequency characteristics of the system are presented.     

沉积温度对碳芯SiC 纤维微观结构的影响

以沥青基碳单丝为基体,一甲基三氯硅烷为碳化硅前驱体,使用通电加热的冷壁CVD工艺,温度在1 473～1 773 K,制备了碳芯SiC纤维.采用扫描电子显微镜和拉曼光谱对纤维的表面形貌及结构进行了表征,研究了沉积温度对其结构的影响.结果表明,SiC涂层为β-SiC晶型.沉积温度的升高引起了沉积速率的增加以及SiC涂层晶粒尺寸的长大.同时,导致碳芯中心区域发生结构重排,引起了该区域取向度的提高以及晶粒尺寸的减小.     

Simulation of a flexible spacecraft motion to evaluate microaccelerations

A method for simulating a flexible spacecraft motion using Lagrange’s quasivelocity formulation is considered. An algorithm of quasivelocity formation by Walsh’s means is proposed. This method can be used to evaluate a quasistatic microacceleration field component in the spacecraft internal environment.     

动态联盟企业异地协同生产调度与控制策略研究

动态联盟作为敏捷制造的组织形式是实现敏捷的关键技术之一。本文提出了基于敏捷制造模式下的动态联盟企业异地协同生产调度与控制的框架模型，并详细探讨了生产调度的协同控制方法与核心问题，借助Internet/Intranet构建了一个协同生产调度与控制的实施模型，为制造业进行分散网络化集成产品开发与制造提供一种参考模型。     

Topical problems of corporative control in aircraft manufacturing

In this paper, the necessity for applying the corporative methods and tools of control over the processes of development, production, and realization of aircraft engineering articles is substantiated. The general structure of aircraft-manufacturing corporation is presented. Some problems of constructing the most advanced computer-aided corporative systems of control in aircraft manufacturing are discussed.     

Features of RadioAstron Mission Control

Support means of the Spektr-R spacecraft flight and features of the Mission Control Center operation and spacecraft control are considered. Software for scheduling and preparing sessions of controlling and simulating for the spacecraft operation are considered. The problems of ballistic navigation support of the spacecraft flight are presented. Ground spacecraft control segment and software for analyzing and imaging telemetric information are considered.     

Thermal conductivity of thermal barrier coatings

The results of experimental studies of the thermal conductivity coefficient of thermal barrier coatings (TBC) are presented. A technique for its determination is proposed and tested. The data of design evaluation of the TBC thickness distribution along the outline of a cooled turbine blade are given.