THE ROLE OF FLUID MECHANICS IN PREDICTING FLUID-STRUCTURE INTERACTIONS: A MATHEMATICAL ANALYSIS

Abstract

Background: Fluid-structure interaction (FSI) plays an important role for studying how structures dynamic response to fluid that surrounds them. Such phenomena are of interest to a number of fields, such as aerospace, biomechanics and civil engineering. The correct emulation of the FSI is only possible by using sophisticated mathematically model based on the fundaments of fluid continuum mechanics. Aim: The objective of this work is to perform a mathematical analysis on FSI based on fluidic OM/media/cl.16.html#1]16] fluid mechanics and numerical approaches to determine the structural responses for different flows and material properties. Method: A computer simulation was carried out with the finite element Arbitrary Lagrangian-Eulerian (ALE) scheme to resolve the interaction between the fluid and the structure. Flow velocity, density, viscosity, and structural compliance were varied systematically. Accuracy, convergence rate and computational time of predictions were compared between monolithic, partitioned and weak numerical coupling techniques.  Results: The results showed that the larger fluid velocity caused a large increase both in the structural deformation and the drag force. Weaker structures showed more drag/lower vibration frequency and increased drag/lift forces resulted from thicker more viscous fluids. Monolithic coupling provided best precision, with the least interface error, at the cost of the greatest computational effort. ALE scheme preserved quality of mesh and prevented it to be wrapped into elements during large deformation. Conclusion: Mathematical modelling of fluid (‘open’) and FSI is capable of describing FSI phenomena over a spectrum of flows. The inclusion of advanced numerical calculations increases the accuracy of the simulation results, thus making them suitable for engineering and biomedical solutions.