利用网格速度理论,计算机翼在锐边突风和1-cos突风下的响应,研究气动非线性和自由度耦合对翼尖加速度和升力系数的影响。采用中心格式有限体积法进行空间离散,并用双时间推进法求解非定常Euler方程。计算了刚性(沉浮)和弹性机翼在锐边突风下的加速度响应,以及刚性机翼(沉浮+俯仰)在1-cos突风下的升力响应过程,并分别与片条理论和六自由度方程的计算结果比较。在低马赫数时,各种方法得到的结果符合得很好,直接验证了网格速度方法在三维弹性和刚性机翼突风响应计算中的准确性,为计算流体力学(CFD)技术在突风响应计算中的应用打下基础。从高马赫数时CFD计算得到的结果可以看出,气动非线性对于机翼突风响应的结果影响比较大,在实际突风响应计算中必须考虑由于非线性带来的影响,而六自由度方程中各个自由度的耦合作用对升力的影响不大。
The grid speed method is used to calculate the sharp-edged and 1-cos gust response of wing configuration using computational fluid dynamics (CFD) tools. The spatial discretization of the Euler equations is performed using the central scheme, and time integration was implemented by the dual time-stepping approach. The sharp-edged gust response analysis of both rigid (plunge) and elastic wing configurations is performed, and the acceleration response is calculated and compared with the strip theory results. The 1-cos gust response analysis of rigid (plunge and pitch) wing configuration is performed, and the lift response is calculated and compared with the six degree of freedom (6-DOF) equation results. The results indicate that at low Mach numbers the application of the grid speed method is an effective way to simulate gust responses. At high Mach numbers, however, nonlinear infection is a very important aspect in the simulation of gust response of wing configurations which should be considered in practical applications,while the coupling in 6-DOF equation does not seriously affect the calculated lift history.
[1] 谢正桐, 周文伯. 超声速机翼-尾翼对突风动态响应的数值方法[J]. 空气动力学学报, 1996, 14(3): 344-348. Xie Zhengtong, Zhou Wenbo. A numerical methodof the wing-tail combination unsteady response to gust[J]. Acta Aerodynamica sinica, 1996, 14(3): 344-348. (in Chinese)
[2] 詹浩, 钱炜祺. 翼型和机翼阵风响应的数值模拟[J].空气动力学学报, 2007, 25(4): 531-536. Zhan Hao, Qian Weiqi. Numerical simulation of gust response for airfoil and wing[J]. Acta Aerodynamica sinica, 2007, 25(4): 531-536. (in Chinese)
[3] 詹浩, 钱炜祺. 弹性机翼阵风响应数值计算方法[J]. 计算力学学报,2009,26(2): 270-275. Zhan Hao, Qian Weiqi. Numerical simulation on gust response of elastic wing[J]. Chinese Journal of Computational Mechanics, 2009, 26(2): 270-275. (in Chinese)
[4] Yang G W. Numerical analyses of discrete gust response for an aircraft[J]. Journal of Aircraft, 2004, 41(6): 1353-1359.
[5] Revah D E. CFD-based models of aerodynamic gust response[J]. AIAA Journal, 2007, 44(3): 888-897.
[6] Revah D E. CFD-based gust response analysis of free elastic aircraft[J]. ASD Journal, 2010, 2(1): 23-34.
[7] Singh R, Baeder J D. Direct calculation of three dimensional indicial lift response using computational fluid dynamics[J]. Journal of Aircraft, 1997, 34(4): 465-471.
[8] Parameswaran V, Baeder J D. Indicial aerodynamics in compressible flow-direct computational fluid dynamic cal- culation[J]. Journal of Aircraft,1997,34(1):131-133.
[9] 郭同庆. 复杂组合体跨音速非定常气动力和颤振计算. 南京:南京航空航天大学航空宇航学院, 2006. Guo Tongqing. Transonic unsteady aerodynamics and flutter computations for complex assemblies. Nanjing: College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, 2006. (in Chinese)
[10] 郁嘉, 林贵平, 吴铭. 弹射座椅减速性能的数值仿真计算[J]. 航空学报, 2006, 27(6): 1033-1038. Yu Jia, Lin Guiping, Wu Ming. Numerical simulation of deceleration performance of ejection seat[J]. Acta Aeronautica et Astronautica Sinica, 2006, 27(6): 1033-1038. (in Chinese)
[11] Jaiman R, Geubelle P, Loth E. Stable and accurate loosely-coupled scheme for unsteady fluid-structure interaction. AIAA-2007-0334, 2007.
[12] Farhat C, Lesoinne M. Two efficient staggered algorithms for the serial and parallel solution of three-dimensional nonlinear transient aeroelastic problems[J]. Computer Methods in Applied Mechanics and Engineering, 2000, 182(3-4): 499-515.
[13] 赵永辉. 气动弹性力学与控制[M]. 北京:科学出版社,2007:219-229. Zhao Yonghui. Aeroelastical mechanics and control[M]. Beijing: Science Press, 2007: 219-229. (in Chinese)
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