关于如何提升新一代研究生学术创新能力的几点思考

本文探讨了如何提升新一代研究生学术创新能力,并从提高学术创新能力的意义、新一代研究生的特点以及新一代研究生培养模式等方面提出了自己的几点思考。     

基于IRIG-B码的运载火箭测发流程同步的软件设计方法

为保证运载火箭在零窗口发射,提出了一种基于IRIG-B码(以下简称B码) 的运载火箭测发流程自动执行的软件设计方法,以确保点火前10min至点火之间的各系统流程的同步。本方案通过UDP网络接收B码的时间,并通过五取三冗余算法,以更新本地的B码时间。随后,再根据预设的点火时间及冗余后的B码时间,计算倒计时,以控制口令流程自动执行。     

VLBI observations to the APOD satellite

The APOD (Atmospheric density detection and Precise Orbit Determination) is the first LEO (Low Earth Orbit) satellite in orbit co-located with a dual-frequency GNSS (GPS/BD) receiver, an SLR reflector, and a VLBI X/S dual band beacon. From the overlap statistics between consecutive solution arcs and the independent validation by SLR measurements, the orbit position deviation was below 10?cm before the on-board GNSS receiver got partially operational. In this paper, the focus is on the VLBI observations to the LEO satellite from multiple geodetic VLBI radio telescopes, since this is the first implementation of a dedicated VLBI transmitter in low Earth orbit. The practical problems of tracking a fast moving spacecraft with current VLBI ground infrastructure were solved and strong interferometric fringes were obtained by cross-correlation of APOD carrier and DOR (Differential One-way Ranging) signals. The precision in X-band time delay derived from 0.1?s integration time of the correlator output is on the level of 0.1?ns. The APOD observations demonstrate encouraging prospects of co-location of multiple space geodetic techniques in space, as a first prototype.     

民用飞机后机身参数化设计探究

通过对民用飞机后机身外形特征的分析,总结了民机后机身外形定义的关键参数,研究后机身外形参数化外形成型的可能性,提出了民机外形参数化设计的方法和思路。     

Investigation on Mechanism of Altitude Characteristic for Air-breathing Pulsed Laser Thruster

Altitude characteristic is of great importance for studying when an air-breathing pulsed laser thruster works in the dense atmosphere condition of 0-30 km altitude. The experimental findings all over the world show that the similar relationship between impulse coupling coefficient and altitude. According to strong explosion theory and an ideal gas model, a dimensionless factor indicating energy law of similitude is introduced, and formula of impulse coupling coefficient is deducted. Then theoretical study of altitude characteristic is carried out and mechanism of altitude characteristic is further explained. The results indicate that there is a maximum value of impulse coupling coefficient if the dimensionless factor equals to 0. 41 in theory, and whether the phenomena of maximum appear or not depends on the range of the dimensionless factor related to altitude. As to a conical nozzle with the fixed length of 120 mm, the relationship between the sonic velocity and the dimensionless factor causes the maximum phenomenon at the altitude of about 12. 5 km, and maximum theoretical impulse coupling coefficient is also found in the experimental investigations. The mechanism of altitude characteristic for air-breathing pulsed laser thruster is discovered in this article, which will provide reference for further research on altitude characteristic.     

多段翼积冰的数值模拟及防冰预测

为研究飞行器翼面积冰预测问题,通过对积冰形成机理的分析,提出了基于经典Messinger模型的积冰表面传质传热的改进模型;通过引入对多段翼空气流场的插值计算,建立了多段翼翼面积冰预测模型;考虑防冰系统向翼面控制体带入的等效热功率,提出了防冰条件下的积冰预测方法.通过对算例的分析对比,数值模拟计算结果与实验数据基本吻合,表明本文提出的结冰计算模型合理,能够用来进行积冰预测分析,为进一步研究翼面结冰后的飞行动力学问题及防除冰系统的设计奠定了基础.      

载人航天器舱门快速检漏仪的可靠性试验与评估方法

载人航天器舱门快速检漏仪是载人航天器舱门及其对接机构对接面气密性检测的测试仪器。为了验证舱门快速检漏仪的可靠性指标水平,按照寿命型和计量型可靠性试验方法的基本思路,通过分析其功能、工作原理和主要故障模式,确定了可靠性特征量,提出了舱门快速检漏仪的可靠性验证试验方法,包括试验方法的选择、试验件状态、试验条件的确定、试验程序、故障判据及可靠性评估方法,并给出了评估结果。     

含滚阻摩擦平面多体系统的建模和数值方法

针对含滚阻和摩擦的平面多体系统,给出了通用的力学模型,利用第一类Lagrange方程建立了系统的动力学方程,为便于约束力的计算,利用局部方法列写约束方程,并以矩阵形式给出了该系统滚阻力偶和摩擦力的广义力.该系统动力学方程是非光滑的,通过建立滚阻定律的互补条件以及光滑铰链约束力的互补条件,给出了具有约束稳定化的基于事件驱动法的数值算法,将非光滑约束力、铰链约束力的求解以及滚轮滑动与粘滞的判断问题统一转化为一个线性互补问题进行求解.对两个算例进行了数值仿真,算例数值结果表明了该方法的可行性和有效性.     

载人航天器密封舱噪声控制与试验

载人航天器密封舱为航天员工作和生活的场所,需对航天员工作区和睡眠区进行噪声控制。文章以某中期驻留载人航天器为例,对其密封舱内的主要噪声源进行识别,并从吸声、隔声、消声、减振4个方面针对主要噪声源进行噪声控制。根据航天器实际噪声源和控制措施,构建了噪声计算模型,通过仿真分析获取了舱体内声压级水平分布,并对舱内噪声分布进行实际测试。仿真结果和测试结果表明噪声控制方案满足指标要求,噪声源识别准确,控制措施有效。     

风力机翼型参数化方法

为满足开发高性能风力机专用翼型所需,提出一种风力机翼型参数化表达方法。首先,基于计算几何理论,开发了一类带形状可调参数的广义Bézier曲线,该曲线不仅保持了Bézier曲线良好的特性,而且具有维持控制多边形不变而实现形状可调的能力,能够更灵活地表达几何外形。然后,针对风力机翼型特点,将此类曲线进行可控性改进,发展了一种风力机翼型参数化表达方法。最后,通过表达常用翼型,以及同其他表达方法进行外形拟合对比,验证了新方法具备全面细致的表达能力,进一步以拟合DU93-W-210为标准算例,与其他方法进行气动特性的吻合表现对比,最终验证了新方法的有效性。