System of simulation training for unmanned aircraft

For proficiently operating an unmanned aircraft, the aircrew must be thoroughly trained. However, using practical equipment to train the aircrew is work of high cost and risk. In this paper, a system of simulation training for unmanned aircraft is introduced. Its function and composition are explained in detail. In practice, the system not only decreases training cost and risk, but also strengthens training effectiveness and diversity     

轮廓仪的多参数微机测量系统

介绍了“轮廓仪的多参数微机测量系统”的构成和技术指标，阐述了设计硬件电路和编制数据处理软件的方法，最后对系统的测量精度进行了测试与比对。     

枝晶生长中的对流效应与形态选择——地基实验研究

通过在生长界面前区域创生液相流动,研究了在稀薄合金中对流对强制性枝晶生长的作用。本文首次报告了对流对强制性枝晶生长的影响。SCN—Acc.模型合金中的定量实验表明,枝晶生长的动力学和形态是温度梯度、生长速度和枝晶端前沿液体流动速度的函数。作为以地面为基础的实验研究,将有助于理解太空凝固试验的结果。     

加速度计参数变化建模方法

通过归纳工程上常用数据建模方法及其应用特点,且结合贮存条件下加速度计零偏和标度因数试验测量数据变化规律,综合给出了建立零偏时间序列模型和标度因数回归模型的详细步骤,并据此建立了贮存条件下加速度计零偏和标度因数的变化模型,所建模型预测的数据与真实数据相比误差很小,充分验证了模型的有效性.所建模型真实地反映了零偏随机性变化规律和标度因数趋势性变化规律的特点,可以为加速度计零偏和标度因数随时间变化的补偿模型提供参考,为加速度计参数长期变化稳定性水平评价提供手段.     

一种改进的数字式波束形成的快速自适应算法

提出了一种改进的数字式波束形成的快速自适应算法,即具有严格约束最小功率的抽样矩阵梯度算法(CSMG)。它综合了传统抽样矩阵梯度、算法和具有严格约束的最小功率自适应算法的优点。计算机模拟表明,此算法波束方向随约束角度而变,自适应调零能力较强,收敛速度也较快。     

Radio fine structures in dm–cm wavelength range associated with magnetic reconnection processes

Radio bursts with fine structures in decimetric–centimetric wave range are generally believed to manifest the primary energy release process during flare/CME events. By spectropolarimeters in 1–2 GHz, 2.6–3.8 GHz, and 5.2–7.6 GHz at NAOC/Huairou with very high temporal (1.25–8 ms) and spectral (4–20 MHz) resolutions, the zebra patterns, spikes, and new types of radio fine structures with mixed frequency drift features are observed during several significant flare/CME events. In this paper we will discuss the occurrence of radio fine structures during the impulsive phase of flares and/or CME initiations, which may be connected to the magnetic reconnection processes.     

Prompt effects of solar wind variations on the inner magnetosphere and midlatitude ionosphere

It is well known that the solar wind can significantly affect high-latitude ionospheric dynamics. However, the effects of the solar wind on the middle- and low-latitude ionosphere are much less studied. In this paper, we report observations that large perturbations in the middle- and low-latitude ionosphere are well correlated with solar wind variations. In one event, a significant (20–30%) decrease of the midlatitude ionospheric electron density over a large latitudinal range was related to a sudden drop in the solar wind pressure and a northward turning of the interplanetary magnetic field, and the density decrease became larger at lower latitudes. In another event, periodic perturbations in the dayside equatorial ionospheric E × B drift and electrojet were closely associated with variations in the interplanetary electric field. Since the solar wind is always changing with time, it can be a very important and common source of ionospheric perturbations at middle- and low-latitudes. The relationship between solar wind variations and significant ionospheric perturbations has important applications in space weather.     

旋转机翼悬停气动特性研究

鸭式旋转机翼(CRW)是一种先进的高速直升机方案,旋翼同时也是机翼,是其最关键气动部件之一。采用结构分区拼接网格技术进行空间离散,分区建立参考系,通过求解多重参考系下的N-S方程来计算旋翼流场,首先以传统的Caradonna-Tung实验旋翼的亚、跨声速悬停流场分析为例验证该方法的可靠性,进而采用该方法对旋转机翼悬停流场进行了数值计算,旋翼拉力计算值和地面实验值吻合较好,结果分析表明旋转机翼的悬停流场有着不同于传统旋翼的流场特性。     

结构隔绝内-外空间的流-热-固耦合仿真应用

为验证和指导高速飞行器的防隔热设计,准确地模拟气动热产生的热量穿透防隔热材料进而影响舱内温度空间分布和时间变化的过程,研究了一种同时求解机体外流场及气动热、机体结构传热及舱内流场温度场仿真计算方法,其中的传热方式包括热传导、热对流及热辐射。采用两套计算模型、两种求解器、一个数据交换文件的计算结构,构建了一种针对流场-热-结构的多场耦合分析方法,实现了对固体隔绝内外流场温度动态变化问题的仿真分析。最后通过计算实例验证了整套计算方法,得到的飞行器舱内温度变化特性能够用于指导高速飞行器的防隔热设计。     

小展弦比飞翼布局新型嵌入面航向控制特性研究

在小展弦比飞翼布局机翼外侧上/下表面分别设计了一组中等后掠角嵌入面,并对其跨声速时的航向控制效果及其流动机理进行了风洞试验和数值模拟研究。计算和试验结果表明,上嵌入面可在小迎角范围通过轴向力和侧向力的共同作用提供稳定的偏航力矩,实现航向控制;当α6°时,由于嵌入面逐渐处于前缘涡的影响范围内,在前缘涡的吸力作用下,嵌入面航向控制效果迅速下降,直至失效,且进行航向控制时存在不利的滚转耦合;下嵌入面可在全迎角范围内提供稳定的偏航力矩,实现航向控制;通过在小迎角范围内使用上嵌入面,α6°时使用下嵌入面,不仅可在全迎角实现航向控制,且不影响飞机的隐身性能。