Coupling Internal and External Mechanics of Swimming Organisms: A Computational Approach

Fauci9805492 本计画是关于水生动物游动的流体动力学，包括鞭毛运动和无脊椎动物游动的研究。 研究者和她的同事们探索了生物体的内力产生机制与外部粘性不可压缩流体的耦合。 一个统一的计算方法可以适用于建模的内部轴丝力学abeating纤毛，力产生内部鞭毛的螺旋体，以及耦合的主动和被动tissueproperties的水蛭的游泳力学。 除了对单个有机体的动力学建模外，还可以研究有机体群体的集体流体动力学相互作用及其影响。 研究者建立了一个数学模型，用于研究流体与生物体的耦合力学系统。 所用的理论方法是浸入边界法。 完全不可压缩的Navier-Stokes方程在一个流体区域内求解，在该区域内，中性浮力生物体处于随时间变化的运动。 该方法的显著特点是在流体动力学方程中用适当的力密度项代替悬浮生物。 这个跨学科的项目采用现代科学计算方法来研究重要的生物过程。 了解细菌的运动和聚集在生物修复中是至关重要的，生物修复是利用细菌降解有毒化学物质的过程。 此外，对纤毛、鞭毛和螺旋体内部机制的研究在医学和生物技术方面也有应用。 在这个项目中开发的计算算法将有助于研究其他生物流体动力学问题，以及有助于高性能计算的专业知识。

Fauci9805492 This project concerns the fluid dynamics of aquatic animallocomotion, a field that encompasses the study of flagellarmotility as well as invertebrate swimming. The investigator andher colleages explore the coupling of the internalforce-generating mechanisms of the organisms with an externalviscous, incompressible fluid. A unified computational approachcan be adapted to model the internal axoneme mechanics of abeating cilium, the force-generating internal flagella ofspirochetes, as well as the coupling of active and passive tissueproperties to the swimming mechanics of a leech. In addition tomodeling the dynamics of a single organism, the collectivehydrodynamic interactions of groups of organisms and theirenvironment can be examined. The investigator has developed amathematical model designed to study the coupled mechanicalsystem comprised of the fluid and the immersed organism. Thenumerical method used is the immersed boundary method. The fullincompressible Navier-Stokes equations are solved in a domain offluid within which neutrally-buoyant organisms undergoingtime-dependent movements are immersed. The salient feature ofthis method is that the suspended organism is replaced bysuitable contributions to a force density term in the fluiddynamics equations. This interdisciplinary project employs modern methods inscientific computing to study important biological processes. Theunderstanding of bacterial motility and aggregation is of vitalimportance in bioremediation, the process by which bacteria areused to degrade toxic chemicals. In addition, the study of theinternal mechanisms of cilia, flagella and spirochetes hasapplications in medicine and biotechnology. The computationalalgorithms developed in this project will be useful in studyingother biofluiddynamic problems as well as contributing toexpertise in high performance computing.