30CrMnSiA钢管外圆磁力研磨工艺的研究

采用化学粘结Ｆｅ＋ＳｉＣ磁性料对３０ＣｒＭｎＳｉＡ钢管外圆进行磁力研磨试验，研究了磨料成分、粒度以及研磨时间与研磨后表面粗糙度的关系，试验所得到的研磨表面粗糙度达到了Ｒａ０．０５μｍ。     

CM-SAF surface radiation budget: First results with AVHRR data

In the phase of redefinition of the EUMETSAT ground segment seven so called Satellite Application Facilities (SAF) each of them serving dedicated user groups have been established in Europe. The SAF on climate monitoring (CM-SAF) will deliver a comprehensive set of climate variables, including from different cloud products, radiation budget at the top of the atmosphere, surface radiation budget and tropospheric humidity. A consistent dataset of cloud and radiation products in a high spatial resolution on a uniform grid is derived. The CM-SAF is a joint project of the German Meteorological Service, EUMETSAT and five other European Meteorological Services. It is dedicated to produce climate datasets using data from instruments onboard of METEOSAT Second Generation and polar orbiting satellites NOAA and METOP. After the development phase, the CM-SAF has started its initial operational phase in the end of 2003. In this context, the algorithms have been implemented at the processing centres and the processing of satellite data from the polar orbiting satellites of NOAA has commenced. This paper gives an overview of the first products of surface radiative fluxes and their validation with selected surface sites.     

捷联姿态解算宏汇编软件

编制捷联姿态解算软件是捷联惯性姿态参考系统研制中的重要一环。由于对计算的实时性和精度都有较高的要求，又在专用的弹上计算机上进行，所以增加了制作的难度。从变量取值范围、比例因子确定、字长选择、程序结构等几方面介绍了捷联姿态解算软件的编制情况。该软件是在导弹计算机上用ＴＭＳ３２０Ｃ２５宏汇编语言编制的。该软件经过地面实物试验，验证了其正确性。     

卫星表面材料体、面电阻率测试方法及电压对体、面电阻率影响的研究

对卫星表面材料的体电阻率、面电阻率的测试方法进行了研究,并设计了测量电极系统,测量了常用热控涂层的体、面电阻率,研究了测量电压对测量结果的影响。     

典型翼型参数化方法的翼型外形控制能力评估

现代飞行器的精细化设计需求要求翼型参数化方法具有精准的翼型外形控制能力。依据标准的风洞模型公差要求,以五个典型翼型作为测试翼型,分别对Hicks-Henne参数化方法、样条参数化方法、PARSEC参数化方法和CST翼型参数化方法的翼型外形控制能力进行评估,依据每个翼型参数化方法的评估结果并结合其固有特点进行适应性分析。结果表明:四种翼型参数化方法对翼型外形的控制能力存在较大差别,具有不同的适用范围。评估典型翼型参数化方法的所得结果可指导设计人员依据具体的设计需求选择适当的翼型参数化方法。     

基于全局信息的粒子群算法翼型综合优化设计

 翼型优化往往需要考虑众多的设计目标和约束条件,对此发展了稳健高效的翼型综合优化方法。在粒子群优化算法中用繁殖策略深度挖掘由Kriging代理模型所获取的全局信息,对基准函数优化、翼型几何外形重构与层流翼型优化问题进行了测试,结果表明该算法可大幅度提高优化速度。将改进的Hicks-Henne翼型参数化方法和雷诺平均Navier-Stokes(N-S)方程流场求解器与优化算法相结合,采用可方便确定权重系数的多目标非线性适应值加权方法,分别对多点、多目标和多约束的超临界翼型与低速翼型进行综合优化,计算结果表明该方法可大大提高气动外形优化的工程实用性。     

航空标准件建库技术研究

由于标准件在航空产品的全部零件中占有较大的比例,因此建立标准件库可以大大地提高产品的设计效率。本文分析了标准件库的系统结构,并论述了在UG/OPEN API开发平台上建立标准件库的方法。     

Effects of surface roughness on the aerodynamic performance of a high subsonic compressor airfoil at low Reynolds number

The aerodynamic performance of compressor airfoil is significantly affected by the surface roughness at low Reynolds number (Re). In the present study, numerical simulations have been conducted to investigate the impact of surface roughness on the profile loss of a high subsonic compressor airfoil at Re = 1.5 × 10⁵. Four roughness locations, covering 10%, 30%, 50% and 100% of the suction surface from the leading edge and seven roughness magnitudes (R_a) ranging from 52 to 525 μm were selected. Results showed that the surface roughness mainly determined the loss generation process by influencing the structure of the Laminar Separation Bubble (LSB) and the turbulence level near the wall. For all the roughness locations, the variation trend for the profile loss with the roughness magnitude was similar. In the transitionally rough region, the negative displacement effect of the LSB was suppressed with the increase of roughness magnitude, leading to a maximum decrease of 14.6%, 16.04%, 16.45% and 10.20% in the profile loss at R_a = 157 μm for the four roughness locations, respectively. However, with a further increase of the roughness magnitude in the fully rough region, the stronger turbulent dissipation enhanced the growth rate of the turbulent boundary layer and increased the profile loss instead. By comparison, the leading edge roughness played a dominant role in the boundary layer development and performance variation. To take fully advantage of the surface roughness reducing profile loss at low Re, the effects of roughness on suppressing LSB and inducing strong turbulent dissipation should be balanced effectively.     

Effect of creep feed grinding on surface integrity and fatigue life of Ni3Al based superalloy IC10

Ni₃Al-based superalloy IC10 is widely used in high temperature components of aero-engines because of its superior mechanical properties. In this paper, the creep feed grinding properties of IC10 were investigated experimentally. The effects of grinding parameters on the grinding forces and temperature were examined. Moreover, the influences of surface roughness and hardening on the high-cycle fatigue life of IC10 specimens were studied. To control the creep feed grinding parameters and enhance the fatigue life of IC10 components, the experimental results were summarized to offer a useful reference point. It is concluded that, the grinding depth is the most important factor which influencing the grinding forces and temperature; the surface roughness is the main and unfavorable factor on the fatigue life of IC10, while the surface hardening has a positive influence on the fatigue life; to obtain a better surface quality and improve the fatigue life of IC 10, the recommended grinding parameter domain involves wheel speed ∈ [15, 20] m/s, feed rate ∈ [150, 200] mm/min, and grinding depth ∈ [0.4, 0.5] mm.