Computational flow in a collapsed tube with wall contact

摘要

Biofluids are transported in deformable vessels. When the transmural pressure is negative, the vessel collapses; opposite walls can come into contact. The dynamics of collapsible pipes depend upon the coupling between the biofluid and the biosolid via the tube law, which is described in the present paper. A brief review of experimental and theoretical modelling is also given, with emphasis on the one-dimensional theory. However, this fruitful model has many limitations; three-dimensional studies must now be carried out. As an illustration, the laminar steady flow has been computed in a rigid pipe corresponding to a highly collapsed tube with wall contact (Reynolds number of 1210). The Navier-Stokes equations, associated to the classical boundary conditions, were solved by a finite element method. Where the opposite walls are in contact, the fluid flows through two small tear-drop-shaped outer passages. In the downstream divergent, in- and up(bottom)ward jets are associated to flow separations and to flow characteristics behind a stationary immersed wall.