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低温推进剂热分层研究
热分层 界面现象 箱体增压
2015/6/27
通过详细分析热分层产生的机理，阐述了低温流体热分层所引起的流体温度分布、气液界面现象以及箱体压力增加过程。对有关流体热分层的试验研究以及数值模拟的文献进行了整理；对不同低温流体工质、箱体初始设置参数及尺寸参数、箱体形状、壁面曲率大小、壁面是否加肋片以及箱体晃动旋转等对热分层的影响进行了分类总结；对不同热分层数学物理模型进行了系统对比。介绍了不同重力水平下，流体流动状态与热分层的关系。归纳了有关热分...
GEO非合作目标超近距相对位姿视觉测量
GEO 在轨服务 非合作目标
2015/6/27
提出一种基于几何特征综合匹配的双目超近距相对位姿视觉测量方法。首先，将失效卫星的矩形太阳帆板作为几何特征，采用综合匹配方法实现了双目图像的高精度匹配，随后基于几何特征指标参数判别和ROI检测方法，实现了卫星太阳帆板特征点组的识别与提取，在此基础上，进一步建立了目标坐标系，通过三维重建完成了超近距阶段失效卫星的相对位姿高精度解算。最后建立了高精度双目视觉超近距相对测量实验系统，结合所提出的综合匹配算...
粗糙物面引起的超声速边界层转捩现象研究
超声速流 风洞实验 数值模拟
2015/6/27
采用风洞实验和数值模拟方法研究平板表面圆柱形粗糙单元引起的M=3超声速边界层转捩问题。实验采用纳米粒子示踪平面激光散射技术（NPLS）对流动结构进行测量。共考察了1mm、2mm和4mm三个不同的粗糙度条件。采用五阶精度加权紧致非线性格式（WCNSE5）对风洞实验进行数值模拟和对比。实验及计算表明：粗糙元对边界层干扰后诱导了尾迹流向涡的形成，流向涡通过抬升机制产生剪切层和流向速度条带等不稳定结构...
Correlation of GPS signal fades due to ionospheric scintillation for aviation applications
Ionospheric scintillation Global Positioning System (GPS) Wide Area Augmentation System (WAAS) Aviation Availability
2015/6/24
Deep and frequent Global Positioning System (GPS) signal fading due to strong ionospheric scintillation is a major concern for GPS-guided aviation in equatorial areas during high solar activity. A GPS...
基于角速率的低配置小型无人机高度控制律设计
控制律 鲁棒伺服 角速率
2015/6/18
采用鲁棒伺服最优控制方法（RSLQR，Robust Servo Linear Quadratic Regulator）设计了基于角速率的某小型无人机高度控制律。该方法将鲁棒指标和时域控制品质相融合，将跟踪误差扩展到系统动态模型中，利用线性二次型最优控制理论，设计了控制律结构和参数，实现了高度的无静差控制，保障了控制器的鲁棒性能。与常规控制器对比结果表明：基于角速率的控制器具有良好的高度跟踪效果和抗...
Then to Now, the CFD Revolution, a Personal and Historical Perspective
Historical Perspective CFD Revolution
2015/6/18
Aside from the contributions of my students to the research of our group, I am
specially indebted to them for their assistance in creating papers and
presentations in electronic form. In recent year...
The research presented has been made possible by the support of the
following organizations:
Airforce Oce of Scienti c Research under grant FA9550-10-1-0418
by Dr. Fariba Fahroo
National Science ...
I am deeply honored to share this Symposium with Phil Roe and Bram Van Leer.
Their work has provided the foundations of modern CFD methods, and
profoundly altered the evolution of the subject.
Computers and Aviation
Computers Aviation
2015/6/18
To trace the parallel development of computing and flight over the last
300 years, culminating in a fusion of engineering, mathematics and
computing in modern aviation.
“From Physics to Daily Life” Colloquium Computers and Aviation
From Physics to Daily Life Computers Aviation
2015/6/18
To trace the parallel development of computing and flight over the last
300 years, culminating in a fusion of engineering, mathematics and
computing in modern aviation.
Time Spectral Method for Rotorcraft Flow with Vorticity Confinement
Vorticity Confi nement Rotorcraft Flow
2015/6/18
These comprise a four dimensional coupled space–time set of
nonlinear equations, which need to be solved simultaneously. For
this purpose we introduce a pseudo time derivative term to
equation (2),...
The first fifty years of aviation were punctuated with
frequent innovations, transforming what were once
daring stunts into an engine of our modern economy.
The second fifty years seems to many, ju...
Supersonic Aircraft Optimization for Minimizing Drag and Sonic Boom
Sonic Boom Minimizing Drag
2015/6/18
A design tool incorporating classical sonic boom theory, computational fluid dynamics
and a multi-objective genetic algorithm was developed for low-boom supersonic aircraft
optimization. Both sonic ...
The high bandwidth and good control authority make the device an ideal
candidate for control of both the rigid body and °exible modes of a °ight
vehicle.