Recent experiments have shown that cones of intermediate apex angles display orientational stability with apex leading in flight. Here we show in experiments and simulations that analogous results hold in the two-dimensional context of solid wedges or triangular prisms in planar flows at Reynolds numbers $\text{Re}\sim 10^2$ to $10^3$. Slender wedges are statically unstable with apex leading and tend to flip over or tumble, and broad wedges oscillate or flutter due to dynamical instabilities, but those of apex half angles between about $40°$ and $55°$ maintain stable posture during flight. The existence of “Goldilocks” shapes that possess the “just right” angularity for flight stability is thus robust to dimensionality. We also show that the stability is robust to moderate changes in shape and Reynolds number.

最近的实验表明，中间顶点角的圆锥体显示定向稳定性，其中顶点在飞行中领先。在这里，我们在实验和模拟中表明，在雷诺数为平面的流动中，实心楔形或三角棱镜的二维上下文中具有相似的结果$\text{回覆}〜\mathrm{1个}{0}^2$ 至 $\mathrm{1个}{0}^3$。细长的楔块在静态上不稳定，先端先导，并倾向于翻转或翻倒，而宽的楔块由于动力不稳定性而振荡或颤动，但顶点的半角介于$40°$ 和 $55°$在飞行中保持稳定的姿势。因此，拥有“恰到好处”的棱角以保持飞行稳定性的“金发姑娘”形状对尺寸具有鲁棒性。我们还表明，稳定性对形状和雷诺数的中等变化具有鲁棒性。