Viscous flow past a collapsible channel as a model for self-excited oscillation of blood vessels.
Motivated by collapse of blood vessels for both healthy and diseased situations under various circumstances in human body, we have performed computational studies on an incompressible viscous fluid past a rigid channel with part of its upper wall being replaced by a deformable beam. The Navier-Stokes equations governing the fluid flow are solved by a multi-block lattice Boltzmann method and the structural equation governing the elastic beam motion by a finite difference method. The mutual coupling of the fluid and solid is realized by the momentum exchange scheme. The present study focuses on the influences of the dimensionless parameters controlling the fluid-structure system on the collapse and self-excited oscillation of the beam and fluid dynamics downstream. The major conclusions obtained in this study are described as follows. The self-excited oscillation can be intrigued by application of an external pressure on the elastic portion of the channel and the part of the beam having the largest deformation tends to occur always towards the end portion of the deformable wall. The blood pressure and wall shear stress undergo significant variations near the portion of the greatest oscillation. The stretching motion has the most contribution to the total potential elastic energy of the oscillating beam.
Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230026, China.
Chao
C
Tang
Department of Mathematical Sciences, Indiana University-Purdue University, Indianapolis, 402 North Blackford Street, Indianapolis, IN 46202, USA.
Luoding
L
Zhu
Division of Vascular Surgery, Department of Surgery, Indiana University-Purdue University, Indianapolis, IN 46202, USA.
George
G
Akingba
Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230026, China. Electronic address: xlu@ustc.edu.cn.
Xi-Yun
XY
Lu
D001794:Blood Pressure / Q000502:physiology*; D001808:Blood Vessels / Q000502:physiology*; D003198:Computer Simulation; D004548:Elasticity; D006801:Humans; D057446:Hydrodynamics; D008954:Models, Biological; D008955:Models, Cardiovascular; D009038:Motion; D009991:Oscillometry; D011312:Pressure; D033081:Shear Strength; D013314:Stress, Mechanical; D013997:Time Factors; D014783:Viscosity
Blood-vessel interaction; Collapsible vessel; Fluid–structure interaction; Self-excited oscillation; Wall shear stress