Numerical Analysis Sub-System

Code identification

After defining all technical requirements, an accurate assessment of the commercial software capabilities was carried out with the aim to select the most suitable numerical code to use in numerical simulation activity. An accurate analysis of published literature has been conducted to identify existing CFD commercial codes and compare their respective capabilities in solving haemodynamic flows of typical biomedical devices, including the two applications of the project.

The identification phase showed the code FLUENT as the best choice for the proposed configuration. No other CFD code has demonstrated to allow for easy and accurate simulation of interaction between rotating parts and fixed diffuser (axial pump) and, at the same time, enable effective fluid-rigid body interaction under moving boundary condition (heart valve). This code also allows high flexibility customisation for User-Defined Functions (UDFs). FLUENT SW (GAMBIT and FLUENT 6.1) was successfully installed and its correct functioning verified on a dedicated multi-processor workstation, based on Linux operative system.

Simulation of test cases using FLUENT 6.1

2D

Moving/ deforming mesh for heast valve simulations	Automatic remesh	Example of calculated velocity distribution

3D

Several rotor/stator interaction models with increasing degree of coupling for axial pump simulation