Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Phys Rev Lett. 2010 Aug 20;105(8):084502. doi: 10.1103/PhysRevLett.105.084502.
We present fundamental solutions of low Reynolds number flows in a stratified fluid, including the case of a point force (Stokeslet) and a doublet. Stratification dramatically alters the flow by creating toroidal eddies, and velocity decays much faster than in a homogeneous fluid. The fundamental length scale is set by the competition of buoyancy, diffusion and viscosity, and is O(100 μm-1 mm) in aquatic environments. Stratification can therefore affect the swimming of small organisms and the sinking of marine snow particles, and diminish the effectiveness of mechanosensing in the ocean.
我们给出了分层流中低雷诺数流动的基本解，包括点力（Stokeslet）和偶极子的情况。分层通过产生环形涡流极大地改变了流动，并且速度的衰减比均匀流体快得多。基本长度尺度由浮力、扩散和粘性的竞争决定，在水生环境中为 O(100 μm-1 mm)。因此，分层会影响小型生物的游泳和海洋雪颗粒的下沉，并降低海洋中机械感应的效果。
