翼型风洞侧壁干扰的数值模拟研究

运用Navier-Stokes数值模拟对翼型模拟试验对风洞侧壁干扰进行模拟，将简单代数湍流模型扩展用于机翼／风洞侧壁结合区流动，分析了风洞实验侧壁干扰问题的形成机理和影响翼型实验侧壁干扰的各种因素，如翼型展长、风洞侧壁边界层厚度及侧壁边界层抽吸等，对实验结果的影响，得出了一些有用的结论。计算格式空间采用中心有限体积离散，时间采用多步Runge-Kutta时间步长格式进行积分。计算结果证明了该方法的可行性和优越性。     

飞机空中加油任务剖面优化设计

介绍了某型飞机执行作战任务途中何时进行空中加油，并按照最大航程截击对飞机各个飞行任务段的飞行性能进行了计算，得出了最佳巡航速度，确定了最优的加油时机和加油量。计算过程中采用了遗传算法，考虑了爬升过程和巡航过程中飞机变质量的难点问题，提高了计算结果的可信度。     

利用林胶茶人工群落减弱台风对橡胶林破坏机理的风洞模拟试验研究

本文研究台风登陆时（中性大层结）胶茶人工群落内部及上部风速的变化，湍流结构的变化及阻力的变化，来分析判断基减弱台风破坏的机理，评定最佳防风效果的林胶茶人工群落方案。试验研究证明台风吹向胶茶人工群落，台风越过和穿过林带，由于气流与树冠，枝叶的冲击与摩作用，使台风风速大大降低，使动能大大损失，使原来动能强和湍流弱的较大尺度旋涡的台风，变成旋涡尺度较小的动能弱湍流强的湍流，湍流能量的增强反映了风速递减率     

街道峡谷湍流流动的风洞试验与数值计算

在１：２５０的风洞模型上,测量街道峡谷的平均流速,湍流度等参数,分析了街道峡谷内的湍流流动状态,探讨了屋顶来流风在街道峡谷内产生复杂流场的主要特征,并用三维湍流流模型对风洞试验模型进行了数值计算,试验和计算结果为研究街道峡谷风环境以及街道峡谷的传热传质过程提供了基础。     

基于MSP430汽车防抱死制动控制器的设计

介绍了一种汽车防抱死制动系统控制器的设计。控制器以MSP430F149单片机为核心,根据防抱死制动系统的工作原理,利用轮速传感器,对轮速进行滤波、放大、整形等实现车轮速度的采集。采用基于车轮滑移率的防抱控制理论,根据车速、轮速来计算车轮滑移率。在硬件设计方面,根据系统选择了MSP430F149单片机,设计出信号输入回路、输出驱动回路、电源部分,给出了系统结构原理图。     

N5A飞机失速警告器的安装与校准

探讨失速警告器的选位安装与校准问题。失速警告器的选位安装与校准均由试飞实验确定。提出了如何调整失速警告器安装位置和安装角的指导性原则,论述了用表速计量失速预警速度的理由。     

利用高速采集系统实现角速度波动的测量

利用自行研制的高速采集系统,通过测量和数据处理软件来实现角速度波动信号的采集和处理,利用定时测角原理实现瞬时角速度的测量,并通过实验验证了该方法的可行性.     

A Possible Transfer Mechanism for the 11-Year Solar Cycle to the Lower Stratosphere

Observational evidence of the 11-year solar cycle (SC) modulation of stratosphere temperatures and winds from the ERA-40 dataset is reviewed, with emphasis on the Northern winter hemisphere. A frequency modulation of sudden warming events is noted, with warmings occurring earlier in solar minimum periods than in solar maximum periods. The observed interaction between the influence of the SC and the quasi biennial oscillation (QBO) on the frequency of sudden warmings is noted as a possible clue for understanding their mechanism of influence. A possible transfer route for the 11-year solar cycle from the equatorial stratopause region to the lowest part of the stratosphere is proposed, via an influence on sudden warming events and the associated induced meridional circulation. SC and QBO composites of zonal wind anomalies show anomalous wind distributions in the subtropical upper stratosphere in early winter. Mechanistic model experiments are reviewed that demonstrate a sensitivity of sudden warmings to small wind anomalies in this region. Various diagnostics from these experiments are shown, including EP fluxes and their divergence and also the synoptic evolution of the polar vortex, in order to understand the mechanism of the influence. Some recent GCM experiments to investigate the SC/QBO interaction are also described. They simulate reasonably well the observed SC/QBO interaction of sudden warming events and appear to support the hypothesis that tropical/subtropical upper stratospheric wind anomalies are an important influence on the timing of sudden warmings.     

Variations of the magnetic fields in large solar flares

We present preliminary results from high resolution observations obtained with the Michelson Doppler Imager (MDI) instrument on the SOHO of two large solar flares of 14 July 2000 and 24 November 2000. We show that rapid variations of the line-of-sight magnetic field occured on a time scale of a few minutes during the flare explosions. The reversibility/irreversibility of the magnetic field of both active regions is a very good tool for understanding how the magnetic energy is released in these flares. The observed sharp increase of the magnetic energy density at the time of maximum of the solar flare could involve an unknown component which deposited supplementary energy into the system. This revised version was published online in August 2006 with corrections to the Cover Date.     

利用虚拟仪器实现角速度波动率的采集和处理

利用NI 的PXI-6281高速数据采集卡来完成角速度波动信号的采集,借鉴信号失真度的概念,分析角速度反馈信号的基波和高次谐波大小,求取高次谐波与基波幅值比,作为角速度波动率.