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在风电叶片三维有限元参数模型中引入了重力产生的附加载荷,仿真计算了风电叶片水平加载方式的静载荷测试中附加载荷产生的水平方向的耦合位移,分析了耦合位移对测试过程中理论计算结果的影响;由于重力的叠加效应,测试中某些截面实际施加的等效载荷可能远超叶片设计的目标测试载荷,建议联合有限元分析,优化叶片安装角度和加载力方向的方法,降低叶片局部截面实际施加等效载荷的过载峰值。 相似文献
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中纬突发E层特性的模拟分析 总被引:2,自引:2,他引:0
从基本的连续性方程出发,并结合运动方程,运用特征线方法求解,在合理的动力学假设条件下,模拟金属离子的汇聚,即Es层的形成.模拟的结果在一定程度上证实了风剪切理论的合理性.通过改变风场和电场模式的输入参量,使模拟的结果体现出不同当地时、不同季节的金属离子汇聚情况,讨论了模拟Es层峰值密度对风场和电场的周日和季节变化的响应,其结果与统计得到的Es层出现率的时间分布特征相似. 相似文献
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Wei LIU Xin MA Ling CHEN Zhenyuan JIA Weixiao LIU Xiao LI Jiakun ZHANG Jiwen LU 《中国航空学报》2018,31(1):89-98
The measurement of position and attitude parameters for the isolated target from a high-speed aircraft is a great challenge in the field of wind tunnel simulation technology. This paper proposes a remote-controlled flexible pose measurement system in wind tunnel conditions for the separation of a target from an aircraft. The position and attitude parameters of a moving object are obtained by utilizing a single camera with a focal length and camera orientation that can be changed based on different measurement conditions. Using this proposed system and method, both the flexibility and efficiency of the pose measurement system can be enhanced in wind tunnel conditions to meet the measurement requirements of different objects and experiments, which is also useful for the development of an intelligent position and attitude measurement system. The position and the focal length of the camera also can be controlled remotely during measurements to enlarge both the vertical and horizontal measurement range of this system. Experiments are conducted in the laboratory to measure the position and attitude of moving objects with high flexibility and efficiency, and the measurement precision of the measurement system is also verified through experiments. 相似文献
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用织女一号火箭在海南站探测的高空风和风切变 总被引:7,自引:4,他引:3
本文介绍了织女一号(ZN-l)火箭测风原理,数据处理方法和两次测风结果.结果指出,在我国低纬地区中层大气中存在非常明显的风切变和相当强的重力波扰动,测风数据与COSPAR国际参考大气CIRA1986及国际标准化组织航空用参考大气ISO5878-1982/ADD.1-1983存在明显差别. 相似文献
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Magnetic Field Fluctuations in the Solar Wind, Foreshock and Magnetosheath: Cluster Data Analysis 总被引:1,自引:1,他引:0
46 magnetosheath crossing events from the two years (2001.2-2003.1) of Cluster magnetic field measurements are identified and used to investigate the characters of the magnetic field fluctuations in the regions of undisturbed solar wind, foreshock, magnetosheath. The preliminary results indicate the properties of the plasma turbulence in the magnetosheath are strongly controlled by IMF orientation with respect to the bow shock normal. The amplitude of the magnetic field magnitude and direction variations behind quasi-parallel bow shock are larger than those behind quasi-perpendicular bow shock. Almost purely compressional waves are found in quasi-perpendicular magnetosheath. 相似文献
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The aim of this paper is to quantify the performance of an Electric Solar Wind Sail for accomplishing flyby missions toward one of the two orbital nodes of a near-Earth asteroid. Assuming a simplified, two-dimensional mission scenario, a preliminary mission analysis has been conducted involving the whole known population of those asteroids at the beginning of the 2013 year. The analysis of each mission scenario has been performed within an optimal framework, by calculating the minimum-time trajectory required to reach each orbital node of the target asteroid. A considerable amount of simulation data have been collected, using the spacecraft characteristic acceleration as a parameter to quantify the Electric Solar Wind Sail propulsive performance. The minimum time trajectory exhibits a different structure, which may or may not include a solar wind assist maneuver, depending both on the Sun-node distance and the value of the spacecraft characteristic acceleration. Simulations show that over 60% of near-Earth asteroids can be reached with a total mission time less than 100 days, whereas the entire population can be reached in less than 10 months with a spacecraft characteristic acceleration of 1 mm/s2. 相似文献
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完成了一种Ma=2.5~4.0冲压发动机用超声速轴对称混合式进气道模型的设计,通过数值模拟和风洞试验,获得了马赫数Ma=2.5,3.0,3.5,4.0,攻角α=0°,3°,6°,8°条件下的超声速轴对称混合式进气道性能。试验结果表明,随着马赫数的增加,总压恢复系数大幅度下降,亚临界稳定范围变窄,流量系数逐渐增加;随着攻角的增大,总压恢复系数和流量系数总体都呈降低趋势,在Ma≥3.0,α=6°时,进气道性能的下降小于5%,亚临界稳定范围变窄。 相似文献