Nearby boundaries create eddies near microscopic filter feeders
Nearby boundaries create eddies near microscopic filter feeders
复制标题
DOI：
10.1098/rsif.2009.0419
复制
发表时间：
2010-05-06
影响因子：
3.9
通讯作者：
Stone, Howard A.
中科院分区：
文献类型：
--
作者：
Pepper, Rachel E.;Roper, Marcus;Stone, Howard A.
我们通过计算、模拟和实验表明，在固着滤食动物附近经常观察到的涡流通常是由于附近边界的存在造成的。我们对常见的滤食性动物 Vorticella 进行了建模，它的直径约为 50 毫米，通过去除自身吸入的海洋或池塘水中的细菌来进食。我们使用分析斯托克斯勒模型和布林克曼流近似，利用窄间隙几何形状来预测由两个平行无滑移边界引起的涡流大小，这两个平行无滑移边界代表经常在其间进行实验观察的滑道。我们还使用三维有限元模拟来完全求解模型 Vorticella 周围的流动，并分析多个附近边界的影响。此外，我们还跟踪活体饲养涡虫周围的颗粒，以确定实验流场。我们的模型彼此之间以及与实验都非常吻合。我们还提供了近似方程来预测由于两个载玻片之间的滤食器的情况以及连接到两个载玻片之间的垂直表面的滤食器的情况的边界而导致的实验涡流尺寸。
We show through calculations, simulations and experiments that the eddies often observed near sessile filter feeders are frequently due to the presence of nearby boundaries. We model the common filter feeder Vorticella, which is approximately 50 mm across and which feeds by removing bacteria from ocean or pond water that it draws towards itself. We use both an analytical stokeslet model and a Brinkman flow approximation that exploits the narrow-gap geometry to predict the size of the eddy caused by two parallel no-slip boundaries that represent the slides between which experimental observations are often made. We also use three-dimensional finite-element simulations to fully solve for the flow around a model Vorticella and analyse the influence of multiple nearby boundaries. Additionally, we track particles around live feeding Vorticella in order to determine the experimental flow field. Our models are in good agreement both with each other and with experiments. We also provide approximate equations to predict the experimental eddy sizes owing to boundaries both for the case of a filter feeder between two slides and for the case of a filter feeder attached to a perpendicular surface between two slides.