A novel 1D flow model for transient FSI simulation of aortic valve

In contrast with costly 3D flow simulations, simple aortic flow models are much more efficient and have applications in non-invasive clinical flow measurement as well as design optimization of prosthetic valves. Existing simple flow models are typically based on the old Bernoulli principle. In this work, we have developed a novel one-dimensional (1D) unsteady flow model based on the momentum and mass conservation equations, which takes into consideration of both valve movement and pressure loss through the valve. We couple this simplified flow model with a 3D FEM model of the thin-leaflet aortic valve as a 1D/3D hybrid model and perform FSI simulations for the valve of different bending rigidity. The nonuniform pressure distribution on the leaflets is included in the simulation. The full 3D FSI model that simulates the 3D pulsatile flow fully coupled with the same valve is used to assess the performance of the simplified flow model. The results show that the hybrid simulation is able to capture reasonably well the 3D deformation sequence of the leaflets, the valve opening area, and the flow rate, especially in the cases of low bending rigidity.