固液动力探空火箭箭载数据采集系统设计

针对固液动力探空火箭在进行测试、飞行试验时,需要实时测量并记录推力、燃料供给速率以及吹除系统工况信息的问题,设计并工程实现了对箭载重要设备输出信号进行监控和采集记录的数据采集系统.以STM32F103RB微控制器为核心,完成了数据采集、存储、传输等电路的设计,并在Real View MDK集成开发环境下,运用C语言完成了控制、测试程序的编写.最后,通过Real View ULINKR仿真器实现了软硬件的联合测试,验证了系统的供电控制、采样频率、工况记录等功能都满足设计要求,完成了对箭载重要设备监控和采集记录的任务.只需修改微控制器内的操控程序,就可将此数据采集系统应用于不同型号的固液动力探空火箭.      

Linkage of the ionospheric peak electron density and height deduced from the topside sounding data

Topside sounding electron density profiles are analyzed to explore interrelations of the F2 layer critical frequency and the peak height for a representative set of conditions provided by ISIS1, ISIS2, IK19 and Cosmos-1809 satellites for the period of 1969–1987. The foF2 and hmF2 are delivered with exponential extrapolation of electron density profile to zero of its 1st derivative. It is shown that the linear regression exists between foF2 and hmF2 under different conditions. The linkage between the two parameters amended to the empirical model of the peak height [Gulyaeva, T.L., Bradley, P.A., Stanislawska, I., Juchnikowski, G. Towards a new reference model of hmF2 for IRI. Adv. Space Res. 42, 666–672, doi:10.1016/j.asr.2008.02.021, 2008] results in an empirical model of the both foF2 and hmF2 expressed by superposition of functions in terms of local-time, season, geodetic longitude, modified dip latitude and solar activity. For the solar activity we use a proxy Fsp index averaged from the mean solar radio flux F10.7s for the past 81 days (3 solar rotations) and F10.7 value for 1 day prior the day of observation. Impact of geomagnetic activity is not discernible with the topside sounding data due to mixed positive and negative storm-time effects. Appreciable differences have been revealed between IRI-CCIR predictions and outcome of the new model which might be attributed to the different techniques of the peak electron density and height derivation, different epochs and different global distribution of the source data as well as the different mathematical functions involved in the maps and the model presentation.     

塞式喷管二次喷射推力矢量控制研究

采用流体二次喷射方案,对塞式喷管发动机进行了不同工况的推力矢量控制冷流试验研究。在试验中,主要对影响推力矢量控制性能的参数:二次流流量、位置、喷射角度、二次流喷射孔的数量以及喷射孔出口面积大小等进行了研究。试验数据表明:二次流的工作参数和环境压力对侧向力的影响比较大。在高空环境下,推力矢量控制效果比较好,但在地面条件下,产生的侧向力比较小。二次流喷射产生侧向力的同时,对轴向力也有一定的增加。     

返回式探空火箭裙锥减速器方案设计及分析

针对传统的探空火箭减速板质量大、展开角度不可调节等缺陷,提出一种新型探空火箭裙锥减速器减速方案。它具有质量小、可改变展开角、展开阻力面积大等优点。针对超声速探空火箭减速器再入时的气动特性,对其外围流场进行了仿真分析,得出了减速器不同锥角对气动特性及过载的影响,并给出了减速器外围流场、压力场以及减速器的应力应变分析,结果表明,减速器所受的气动阻力与其锥角有明显关系,具有非线性特点,且减速器的最大应力小于许用应力。该方案可为探空火箭的回收及新型减速器的设计提供一定的参考依据。     

Index allocation for a reusable LOX/CH4 rocket engine

Reusable rocket engines are the core components of reusable launch vehicles, and have thus become a major focus of aerospace engineering research in recent years. In practice, subsystem design is based on the overall index allocation of an engine; therefore, a multidisciplinary optimization approach is necessary. In this study, design of a reusable methane/liquid oxygen (LOX/CH4) rocket engine with a gas generator cycle was investigated using multidisciplinary optimization. Two parameters were chosen as design variables: pressure and fuel mix ratio of the main combustion chamber. Optimization objectives were specific impulse, structural mass, and life cycle cost of the reusable rocket engine, and constraints were assigned to each discipline according to rocket design requirements. Then, an optimization model was developed, and optimal design parameters were acquired for the LOX/CH4 rocket engine. The proposed method is effective for designing the index allocation of reusable rocket engines and takes into account the multidisciplinary nature of complex systems.     

火箭低空级间热分离初期流场特性数值模拟

采用耦合求解轴对称非定常NS方程与一维分离动力学方程的方法,对多级火箭低空级间热分离初期过程进行数值仿真。依据仿真结果描述低空级间热分离初期流场的两种典型结构：内部为喷管扩张段流动分离以及外部为级间缝隙横向喷流与超声速外流的干扰流场;给出两种典型流场结构中位于上面级弹体表面（喷管内）的流动分离点位置以及壁面压力分布随仿真时间的变化;初步估算流动分离线偏斜时内外流动分离区域对上面级弹体的干扰力矩。通过分析数值模拟与力矩估算结果,发现在低空级间热分离内外流场中流动分离激波后方形成的高压区域是上面级所受干扰力矩的重要来源。研究结论可为级间热分离过程干扰机理研究提供理论方向,为级间热分离时序设计提供参考。     

火箭基组合推进研究现状与前景

对国内外火箭基组合推进系统(RBCC)的研究动态和进展情况进行了总结,阐述了不同时期火箭基组合推进研究计划的重点和所取得的研究成果。分析了火箭基组合推进系统涉及的多项关键技术及其研究进展。论述了火箭基组合推进在两级入轨可重复使用天地往返系统、临近空间及空天飞行器和单级入轨方面的应用前景,并对国内这方面的研究提出了建议。     

大推力速燃火箭发动机蜂巢状装药的设计与理论分析

针对速燃火箭发动机大推力短燃时的特点,提出一种满足此要求的新型装药——蜂巢状装药,并对该药型的内弹道特性、燃面规律和力学特点作出了定性和定量分析,对速燃发动机的装药设计有一定的借鉴意义。     

火箭发动机固体药柱的X射线照相检验

介绍复合包敷层厚壁固体药柱的Ｘ射线检验透照工艺的设计和检测结果的评价。可发现气孔和装药不均匀等缺陷,检测出的最小缺陷为φ３ｍｍ的气孔。     

姿控发动机推力测量系统的动态建模与补偿

在姿控发动机的瞬态推力测量中,推力测量系统的动态特性是影响推力准确测量的一个至关重要的因素。根据姿控发动机推力测量的特点,针对某型号姿控发动机设计了专用的试车台架,采用了动态标定、动态补偿和计算机仿真有机结合的方法,对推力测量系统动态特性的改善进行了研究。仿真结果表明,此方法在改善推力测量系统动态性能方面是行之有效的,可将其进一步推广到其它动态测量系统。