Application of the Finite-Volume Method to Fluid-Structure Interaction Analysis

This paper describes the numerical simulation of steady flow through severely stenosed tubes and the development of a fully coupled fluid-solid solver, capable of predicting the effects of fluid pressure and wall shear stress on the elastic tube wall. This particular type of interaction occurs commonly in physiological flows. Whilst geometrically simple, even with a rigid wall this type of flow exhibits many complex phenomena such as re-circulation and transition to turbulence, both of which make numerical simulation difficult. Initially, flow simulations are reported for a rigid walled tube over a range of physiologically relevant flow rates. Laminar simulations were only successful for Reynolds numbers of less than 300; deviation from the experimental data occurred at the experimentally observed point of transition. Computations using a low-Reynolds-number turbulence model proved successful for Reynolds numbers greater than 1500, with results being in good agreement with experimental data. Following these rigid-wall CFD simulations, a finite-volume based method for solving solid body stress analysis problems has been developed, and the results of a validation exercise show good agreement with analytical solutions. This solid body solver has then been coupled to the CFD code to allow fully coupled fluid-structure interaction (FSI) analyses of flow through a compliant walled stenosis to be performed. Initial results from such coupled cases show a reasonably accurate response of the wall deformation to the flow rate