当代金属类阻尼材料及其应用

论述了金属类阻尼材料的减振降噪机理，介绍了具有代表性的各种阻尼材料的物理机械性能，以及它们的应用情况等。     

超声速进气道湍流流场的数值模拟

采用有限体积法数值模拟了超声速进气道的湍流流场,改进了离散纳维尔－斯托克斯方程中粘性项的方法,使之具有较好的守恒性,研究使用了变系数的隐式残差光顺等加速收敛技术,并讨论了超音来流、收敛型进气道复杂流场初场的给定方法,所得到的数值解正确地展示了流场的复杂激波结构。     

Cosmic ray anisotropies in the outer heliosphere

The observation of the directional distribution of energetic and cosmic ray particles has been done with the Voyager spacecraft over a long period. Since 2002, when the first flux enhancements of charged particles associated with the approach of Voyager 1 to the solar wind termination shock were observed, these anisotropy measurements have become of special interest. They play an important role to understand the magnetic field and shock structure and the basics of the modulation of cosmic ray and anomalous particles at and beyond the termination shock. They also serve as motivation to study the spatial behavior of galactic and anomalous cosmic ray anisotropies with numerical modulation models in order to illustrate how the radial anisotropy, at different energies, change from upstream to downstream of the termination shock. Observations made by Voyager 1 indicate that the termination shock is a complicated region than previously thought, hence the effects of the latitude dependence of the termination shock’s compression ratio and injection efficiency on the radial anisotropies of galactic and anomalous protons will be illustrated. We find that the magnitude and direction of the radial anisotropy strongly depends on the position in the heliosphere and the energy of particles. The effect of the TS on the radial anisotropy is to abruptly increase its value in the heliosheath especially in the A > 0 cycle for galactic protons and in both polarity cycles for anomalous protons. Furthermore, the global effect of the latitude dependence of the shock’s compression ratio is to increase the radial anisotropy for galactic protons throughout the heliosphere, while when combined with the latitude dependence of the injection efficiency this increase depends on modulation factors for anomalous protons and can even alter the direction of the radial anisotropy.     

有烧蚀气体产物影响的化学非平衡粘性流数值计算研究

本文是针对高超声速绕流钝锥体再入飞行器，研究有烧蚀气体产物影响的化学非平衡反应粘性流ＮＳ方程数值计算方法。通过带有化学源项的ＮＳ方程对流动作数值模拟，总的连续方程由单个组元守恒方程组代替。对１３个化学组元，２６个气相化学反应，以及２个气相－固相化学反应，研究烧烛碳－空气的化学反应系统，并与纯空气化学反应系统的计算结果进行比较。利用二阶迎风ＴＶＤ差分格式和激波捕捉法，计算球锥体头部和身部化学非平衡粘性流场     

冲击载荷作用下的界面扩展裂纹

本文给出了在不同材料界面上扩展裂纹动力学问题解的一般表示。文中利用结合面的边界条件,将问题中所有各量用单一未知函数表示。利用复变函数理论,我们将在不同材料界面上受冲击载荷作用的扩展裂纹问题化为解析函数理论中的Keledysh-Sedov混合问题。文中给出这一问题的闭合解,并且给出了不同材料常数及裂纹扩展速度对应力场分布及应力强度因子的影响。     

Reverse shock acceleration of electrons and protons at mid-heliolatitudes from 5.3-3.8 AU

We examine the intensity, anisotropy and energy spectrum of 480–966 keV protons and 38–315 keV electrons observed by the HI-SCALE instrument on Ulysses associated with Corotating Interaction Regions (CIR) from mid-1992 to early 1994. The particle events are most clearly ordered by the reverse shocks bounding the CIRs. The bulk of the ion fluxes appear either straddling, or with their maximum intensity following, the reverse shock. The electron intensities rise sharply to their maximum upon the passage of the reverse shock, and are delayed with respect to the protons. We believe that following acceleration at the reverse shock the electrons re-enter the inner heliosphere and mirror, to return to the reverse shock for repeated acceleration. This process is more effective for electrons (vc/2) than for ions, and also favours the higher velocity electrons, which accounts for the observed spectral hardening with latitude.     

衬垫材料冲击特性测量数据的精度验证

本文提出了在冲击状态下对衬垫材料特性进行测量时，所获实验数据的精度验证方法，根据测量原理，作者首先进行了精度验证公式的推导，据以定义了精度验证因子。然后利用所获验证公式对实验测量数据进行了定量计算，并与验证因子的理论值加以对比。对比结果表明：作者在衬垫材料冲击特性的实验研究中所获测量数据具有足够的精度。本文所提出的精度验证方法亦可用于其它场合。     

固体火箭发动机冲击响应分析中改进的Wilson－θ法

在Ｗｉｌｓｏｎ－θ法基础上引入参数γ，提出了修正的振动平衡方程和初始条件表达式。研究了新方法和稳定性和γ系数的取值范围，并以某些导弹的发动机壳体为算例和实验对象，验证了新方法的正确性在抑制超调现象方面有效性。     

脉冲爆震发动机快起爆的二维数值模拟

为研究脉冲爆震发动机的点火过程，用二维欧拉方程和Korobeinikov两步爆震模型对爆震波快起爆过程进行了数值模拟研究。用高温高压未燃气体点火方式来模拟试验中的电火花塞点火。研究表明：电火花塞的能量不足以直接点燃爆震波，爆震波是在经历了一系列反射激波的相互作用后最终建立的。激波．爆震波转捩是快点火过程，是爆震波建立的一个非常重要的机理。在设计点火装置时，火花塞要尽可能靠近壁面和拐角，以便产生高强度的反射激波。同时还要控制反射激波的方向，使之向未燃气体中顺利传播，才能起到很好的点火效果。