Application of an unstructured grid algorithm to artificial heart valve simulations.

Area of Science:

• Biomedical Engineering
• Computational Fluid Dynamics
• Cardiovascular Science

Background:

• Mechanical heart valve (MHV) flow patterns are complex due to multiple passages and moving leaflets.
• Accurate numerical simulation of unsteady MHV flows presents significant computational fluid dynamics (CFD) challenges.
• Conventional methods using structured grids struggle with grid skewness and moving boundaries.

Purpose of the Study:

• To develop and present an advanced numerical method for simulating blood flow in mechanical heart valves.
• To address the limitations of existing CFD techniques in handling complex geometries and moving parts.
• To investigate the differences between steady and unsteady flow solutions for MHV.

Main Methods:

• An unstructured moving grid finite volume method was developed for heart valve simulations.
• The Navier-Stokes equations were discretized using a finite volume scheme on a tetrahedral mesh.
• The method allows for automatic mesh generation with commercial software.

Main Results:

• The proposed method successfully simulated the time-varying flow patterns around a tilting disk mechanical heart valve.
• Significant discrepancies were observed when comparing unsteady flow solutions with traditional steady-state analyses.
• The unstructured grid approach effectively handled the complex geometry and leaflet motion.

Conclusions:

• The unstructured moving grid finite volume method offers a robust solution for simulating complex MHV hemodynamics.
• Unsteady flow simulations are crucial for accurately understanding MHV performance, revealing limitations of steady-state assumptions.
• This approach enhances the accuracy and feasibility of CFD in cardiovascular device research.