This work is a numerical and experimental study of a rectangular thin plate undergoing stall flutter at Mach 0.8. This constitutes one of the first studies of this kind where three-dimensionality is fully implemented in a numerical simulation including the test-section effects characterizing wind-tunnel experiments. In order to break down the fluid–structure interaction to its main driving phenomena, an aerodynamic model is proposed that is based on computationally inexpensive steady-state simulations. Two types of dynamic instability are observed in the numerical simulations; Flutter by mode coalescence is promoted at zero flow incidence, however, high bending precludes this from happening for higher values of angle of attack. Stall flutter is instead a nonlinear one-degree type of instability. Both of these instability mechanisms can be explained in terms of hysteretic behaviour of the pressure distribution, which becomes more pronounced at high angles of attack, when a large separation region is formed. Tests were conducted employing titanium alloy plates in order to survive the aerodynamic loads characterizing the wind-tunnel initial transient. However, due to wall interference, high bending was promoted so that the internal stress exceeded the yield values before flutter could be measured. Numerical simulations were in general agreement with the experiment in terms of both amplitude and oscillation frequency.

中文翻译：

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跨音速前缘失速颤振：建模、仿真和实验

这项工作是对矩形薄板以 0.8 马赫的失速颤振进行的数值和实验研究。这是此类研究的首批研究之一，其中三维度在数值模拟中得到充分实现，包括表征风洞实验的测试段效应。为了将流固相互作用分解为其主要驱动现象，提出了一种基于计算成本低廉的稳态模拟的空气动力学模型。在数值模拟中观察到两种类型的动态不稳定性；在零流量入射时促进了模态合并的颤振，但是，高弯曲度阻止了这种情况在较高攻角值下发生。相反，失速颤振是一种非线性单度不稳定性。这两种不稳定机制都可以用压力分布的滞后行为来解释，当形成大的分离区域时，这种滞后行为在高攻角下变得更加明显。采用钛合金板进行测试，以便承受表征风洞初始瞬态的空气动力载荷。然而，由于壁的干扰，导致了高弯曲，使得在颤振测量之前内应力就超过了屈服值。数值模拟在振幅和振荡频率方面与实验基本一致。