Currently, biomechanical simulations of blood vessels and organs are widely used in medical research, and it is expected to realize rapid and accurate medical diagnosis by personalized biological simulations for each individual using high-speed and high-precision 3D modeling of the body internal geometry by Multi Detector-row Computed Tomography (MDCT) and Magnetic Resonance Imaging (MRI). In particular, biomechanical simulation approach using Open Source Software (OSS) has been developed for use in the medical field, and recently, its application to more challenging multiphysics simulation has been studied. However, OSS has many issues such as assurance of accuracy and validity of the analysis, the computation time and stability of Fluid-Structure Interaction (FSI), and the lack of analysis functions for complex phenomena. In particular, blood flow simulation using OpenFOAM, a fluid analysis OSS, has issues in the representation of blood pressure changes caused by pulsation and body movement, and the stability of coupled analysis in conjunction with other structural analysis software. In this study, we added the Windkessel model, which is one of the models for expressing blood pressure changes, to OpenFOAM and developed a two-way coupled multi-physics simulation approach using OpenFOAM and CalculiX. As an example of personalized biomechanical simulation, we applied the method to simulate blood flow in the thoracic aorta and evaluated its effectiveness.
