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三维副翼铰链力矩计算 总被引:1,自引:0,他引:1
数值模拟了带副翼偏转构型的二维、三维亚、跨、超声速来流情况的绕流流场,采用有限体积方法和AUSM+迎风格式数值求解N-S方程,四步龙格-库塔时间推进,湍流模型为Baldwin-Lomax和Spalart-Allmaras湍流模型。二维模拟压强分布与实验数据以及CFD软件模拟结果吻合较好。采用交错对接网格,数值模拟了不同副翼偏角和缝隙、来流马赫数、迎角和雷诺数的三维构型流场。通过舵面铰链力矩与实验数据的对比分析表明了该数值方法模拟此类复杂流场的可靠性和舵面铰链力矩计算的有效性。发现并研究了亚声速来流时铰链力矩随迎角的反向变化趋势,初步分析了副翼的缝隙和雷诺数效应。 相似文献
215.
Model Development and Adaptive Imbalance Vibration Control of Magnetic Suspended System 总被引:2,自引:1,他引:1
Tang Liang Chen Yiqing 《中国航空学报》2007,20(5):434-442
对星载磁悬浮单框架控制力矩陀螺,建立其转子的平动与转动的动力学方程。所建模型反映了转子的动、静不平衡特性,以及转子运动与框架、星体运动的耦合关系。模型是主动磁悬浮控制与动框架效应分析的基础。对动、静不平衡量未知的转子,设计了自适应对中控制器。在分散PD、比例交叉反馈控制器与高低通滤波器的基础上,通过动、静不平衡量的辨识与补偿控制,使转子绕其惯量主轴旋转,衰减角动量交换执行机构高速转子因不平衡而对基座产生的干扰力,消除星上主要颤振源,达到降低卫星姿态抖动的目的。 相似文献
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《中国航空学报》2016,(6):1527-1540
A generic aircraft usually loses its static directional stability at moderate angle of attack (typically 20–30?). In this research, wind tunnel studies were performed using an aircraft model with moderate swept wing and a conventional vertical tail. The purpose of this study was to investigate flow mechanisms responsible for static directional stability. Measurements of force, surface pressure and spatial flow field were carried out for angles of attack from 0? to 46? and sideslip angles from ?8? to 8?. Results of the wind tunnel experiments show that the vertical tail is the main contributor to static directional stability, while the fuselage is the main contributor to static directional instabil-ity of the model. In the sideslip attitude for moderate angles of attack, the fuselage vortex and the wing vortex merged together and changed asymmetrically as angle of attack increased on the wind-ward side and leeward side of the vertical tail. The separated asymmetrical vortex flow around the vertical tail is the main reason for reduction in the static directional stability. Compared with the wing vortices, the fuselage vortices are more concentrated and closer to the vertical tail, so the yaw-ing moment of vertical tail is more unstable than that when the wings are absent. On the other hand, the attached asymmetrical flow over the fuselage in sideslip leads to the static directional instability of the fuselage being exacerbated. It is mainly due to the predominant model contour blockage effect on the windward side flow over the model in sideslip, which is strongly affected by angle of attack. 相似文献
218.
一种轴承摩擦力矩测试方法及其测试系统 总被引:1,自引:0,他引:1
介绍了一种利用磁线圈施矩的轴承摩擦力矩的测试方法,给出了测试系统的组成框图,并对测试中的数据处理作了简要说明 相似文献
219.
三轴转台运动耦合作用的仿真及实验研究 总被引:1,自引:0,他引:1
分析了三轴转台运动耦合作用的规律,在数学模型的基础上,探讨了仿真计算和实验验证的方法,并给出了相应的实验结果,证实了分析、计算的正确性,从而为进一步的研究工作提供了依据。 相似文献
220.
The mechanism of a retracting cantilevered beam has been investigated by the invariant and energy-based analysis. The time-varying parameter partial differential equation governing the transverse vibrations of a beam with retracting motion is derived based on the momentum theorem. The assumed-mode method is used to truncate the governing partial differential equation into a set of ordinary differential equations (ODEs) with time-dependent coefficients. It is found that if the order of truncation is not less than the order of the initial conditions, the assumed-mode method can yield accurate results. The energy transfers among assumed modes are discussed during retrac-tion. The total energy varying with time has been investigated by numerical and analytical methods, and the results have good agreement with each other. For the transverse vibrations of the axially retracting beam, the adiabatic invariant is derived by both the averaging method and the Bessel function method. 相似文献