Piston Theory-A New Aerodynamic Tool for the Aeroelastician
Piston Theory-A New Aerodynamic Tool for the Aeroelastician
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DOI：
10.2514/8.3740
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发表时间：
1956-12
期刊：
影响因子：
--
通讯作者：
H. Ashley
中科院分区：
文献类型：
--
作者：
H. Ashley
描述了具有代表性的应用，说明了通过使用统称为“活塞理论”的某些空气动力学技术，可以在多大程度上简化高速非定常气动弹性问题的求解。基于Hayes和Lighthill最初提出的物理模型，Landahl利用厚度比为8的幂和飞行马赫数M的倒数展开，系统地发展了翼型和有限机翼的活塞理论。当8/M和8/M的贡献可以忽略时，该理论预测了机翼表面的局部压力和机翼运动产生的流体速度的法向分量之间的点函数关系。然后，气动弹性方程中的广义力的计算，如颤振行列式，总是归结为假定的运动模式的初等积分。
Representative applications are described which illustrate the extent to which simplifications in the solutions of high-speed unsteady aeroelastic problems can be achieved through the use of certain aerodynamic techniques known collectively as "piston theory." Based on a physical model originally proposed by Hayes and Lighthill, piston theor}^ for airfoils and finite wings has been systematically developed by Landahl, utilizing expansions in powers of the thickness ratio 8 and the inverse of the flight Mach Number M. When contributions of orders 8/M and 8/M are negligible, the theory predicts a point-function relationship between the local pressure on the surface of a wing and the normal component of fluid velocity produced by the wing's motion. The computation of generalized forces in aeroelastic equations, such as the flutter determinant, is then always reduced to elementary integrations of the assumed modes of motion.