Fluid-structure coupled CFD simulation of the left ventricular flow during filling phase

Area of Science:

• Biomedical Engineering
• Computational Fluid Dynamics
• Cardiac Mechanics

Background:

• Fluid-structure interaction (FSI) simulations are crucial for understanding heart function.
• Accurate modeling of the left ventricle (LV) filling phase is essential for diagnosing cardiac conditions.

Purpose of the Study:

• To verify a commercial software-based FSI scheme for simulating left ventricular filling.
• To assess the scheme's ability to handle large deformations and provide accurate physiological data.

Main Methods:

• Employed the finite volume method for fluid dynamics (Navier-Stokes equations) and the nonlinear finite element method for structural mechanics.
• Implemented a unified system approach, solving coupled fluid and structure equations simultaneously at each time step.
• Simulated LV filling in a 3D ellipsoidal thin-wall model with a time-varying Young's modulus.

Main Results:

• Achieved smooth convergence of the FSI coupling despite significant ventricular deformation.
• Simulated results for pressure-volume relationships, pressure distribution, velocity vectors, and vortex patterns showed good qualitative and quantitative agreement with existing data.
• Demonstrated the scheme's feasibility for simulating complex cardiac dynamics.

Conclusions:

• The validated FSI scheme is a promising tool for realistic left ventricular flow simulation.
• Future improvements include incorporating myocardial constitutive laws and using more patient-specific heart geometries.
• This approach holds potential for enhanced heart function investigations and clinical applications.