论文标题
简单的剪切流不稳定性的证明
A simple demonstration of shear-flow instability
论文作者
论文摘要
我们描述了一个简单的课堂演示，展示了流体动力的不稳定性。演示只需要一桶水，一根绳子和一些二手的蓝绿色或咖啡地。我们认为，至少在后期，不稳定性的机制是二维的正压（剪切流）不稳定性，我们提供了支持这一点的证据。我们显示了等效的基本二维数值非线性模型的结果，该模型模拟了与在铲斗演示中观察到的相当的行为。修改的模拟表明，不稳定性不取决于域的曲率，而是取决于速度曲线。
We describe a simple classroom demonstration of a fluid-dynamic instability. The demonstration requires only a bucket of water, a piece of string and some used tealeaves or coffee grounds. We argue that the mechanism for the instability, at least in its later stages, is two-dimensional barotropic (shear-flow) instability and we present evidence in support of this. We show results of an equivalent basic two-dimensional numerical non-linear model, which simulates behavior comparable to that observed in the bucket demonstration. Modified simulations show that the instability does not depend on the curvature of the domain, but rather on the velocity profile.
