Computational Fluid Structure Interaction - Computational Hemodynamics: Theory, Modelling and Applications - page 94

Chapter 5
Computational Fluid Structure Interaction

5.1 Introduction

In a Fluid-Structure-Interaction model, (FSI) pressure forces caused by the fluid
flow is applied onto a structure. With sufficient loading, the structure deforms and
creates a new boundary for the fluid flow analysis. The interaction between fluid
and solid take place at a shared interface or boundary. Force loadings and structural
deformation results are passed from one analysis to the other and hence is given the
name fluid-structure interaction.
This chapter introduces the fluid dynamics and structural mechanics set of equa-
tions. These sets of equations are applied to the separate computational domains
that represent either the fluid or structural component. The domains are connected
together via a common boundary where boundary conditions and constitutive mod-
els are applied.
This chapter focusses on obtaining a physical understanding of the applied equa-
tions avoiding details or complicated proofs of the equations. Furthermore the en-
ergy conservation equations have been left out as it is not essential to the basic
understanding of FSI modeling. For a more complete description of these equa-
tions, the interested reader can refer to several topics on: continuum mechanics
(Lai et al. 2009; Reddy 2013); structural dynamics (Craig and Kurdila 2006; Paz
and Leigh 2004) and; computational fluid dynamics (Tu et al. 2012; Versteeg and
Malalasekera 2007).

5.2 Introduction to Fluid Dynamics

The fluid dynamics equations are mathematical statements of the conservation laws
in physics. It describes the transport of mass, momentum, and energy through a
physical domain. These equations are:

• the conservation of mass;