Developmentof a Numerical Model to Describe Steady一个数值模型来描述稳定发展.docVIP

Development of a Numerical Model to Describe Steady Streaming in Unsteady Axisymmetric Biological Flows in a Geomery with a Slowly Varying Cross-Section Laboratory of Computational Engineering Dr. Mark Sawley Laboratory of Fluid Mechanics Prof. Peter Monkewitz - Radboud Nelissen Anthony Claude Development of a Numerical Model to Describe Steady Streaming in Unsteady Axisymmetric Biological Flows in a Geomery with a Slowly Varying Cross-Section Laboratory of Computational Engineering Dr. Mark Sawley Laboratory of Fluid Mechanics Prof. Peter Monkewitz - Radboud Nelissen Anthony Claude Abstract Cerebrospinal fluid moves from the cranial cavities all along the cerebrospinal canal in a pulsatile way. Its flow has been studied here for various geometries. From the basic case of a tube to a model of an idealized anatomical case, velocity profile and flow behaviour were plotted, analysed and compared. This bi-dimensional study takes into account variation of geometry of the cerebrospinal canal and pulsatile character of the flow. A data base relating variation of internal and external wall for an adult has been realized with Visual Human Server 1 . This research allows determining Reynolds and Womersley numbers average for a given region of the spinal canal. Quantitative solutions of unsteady analysis through a cylindrical tube and qualitative results concerning streamline stream in geometries with slowly variations of section have been found . Finally comparison were made between computational calculations made in 1998 by A.Sarkar and G. Jayaraman2 and Fluent calculations for a similar issue. 1 http://visiblehuman.epfl.ch/vhve.php 2 Correction to flow rate - pressure drop relation in coronary angioplasty: steady straeming effect CONTENTS 2 Contents I Basic Fluid Mechanics Applied to Biological Flows 4 II Womersley Number’s Influence on Biological Flows 5 1 Introduction 5 2 Pulsatile flow through a tube 6 2.1 Hypotheses . . . . . . . . .