An immersogeometric variational framework for fluid–structure interaction: application to bioprosthetic heart valves

By David Kamensky, Ming-Chen Hsu, Dominik Schillinger, John A. Evans, Ankush Aggarwal, Yuri Bazilevs, Michael S. Sacks, Thomas J. R. Hughes. Computer Methods in Applied Mechanics and Engineering, 2014

484 citations recorded by the source corpus.

In this paper, we develop a geometrically flexible technique for computational fluid–structure interaction (FSI). The motivating application is the simulation of tri-leaflet bioprosthetic heart valve function over the complete cardiac cycle. Due to the complex motion of the heart valve leaflets, the fluid domain undergoes large deformations, including changes of topology. The proposed method directly analyzes a spline-based surface representation of the structure by immersing it into a non-boundary-fitted discretization of the surrounding fluid domain. This places our method within an emerging class of computational techniques that aim to capture geometry on non-boundary-fitted analysis meshes. We introduce the term “immersogeometric analysis” to identify this paradigm. The framework starts with an augmented Lagrangian formulation for FSI that enforces kinematic constraints with a combination of Lagrange multipliers and penalty forces. For immersed volumetric objects, we formally eliminate the multiplier field by substituting a fluid–structure interface traction, arriving at Nitsche’s method for enforcing Dirichlet boundary conditions on object surfaces. For immersed thin shell structures modeled geometrically as surfaces, the tractions from opposite sides cancel due to the continuity of the background fluid solution space, leaving a penalty method. Application to a bioprosthetic heart valve, where there is a large pressure jump across the leaflets, reveals shortcomings of the penalty approach. To counteract steep pressure gradients through the structure without the conditioning problems that accompany strong penalty forces, we resurrect the Lagrange multiplier field. Further, since the fluid discretization is not tailored to the structure geometry, there is a significant error in the approximation of pressure discontinuities across the shell. This error becomes especially troublesome in residual-based stabilized methods for incompressible flow, leading to problematic compressibility at practical levels of refinement. We modify existing stabilized methods to improve performance. To evaluate the accuracy of the proposed methods, we test them on benchmark problems and compare the results with those of established boundary-fitted techniques. Finally, we simulate the coupling of the bioprosthetic heart valve and the surrounding blood flow under physiological conditions, demonstrating the effectiveness of the proposed techniques in practical computations.

Subfields: Computational Mechanics, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/462badabb8a33dae0346d2c0d9c067d6c5caf59f

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Citations in the corpus

The variational collocation method (2016, background): “, in solid mechanics [24, 25, 26, 27, 28, 29], fluid dynamics [10, 30, 31, 32], phase-field modeling [33, 34, 35], contact mechanics [36, 37], biomechanics [38, 39] and fluid-structure interaction [40, 41, 42, 43].”
The non-symmetric Nitsche method for the parameter-free imposition of weak boundary and coupling conditions in immersed finite elements (2016, unknown): “For example, immersed finite element concepts have been employed to resolve multi-phase flow interfaces [7, 31], to deal with trimmed CAD surfaces [17, 50, 61, 65] and image based geometries [62, 68, 69], to prevent mesh updating and mesh distortion [10, 15, 21, 55], or to handle fluid–structure int”
Isogeometric Kirchhoff–Love shell formulations for general hyperelastic materials (2015, methodology): “The pressurized diastolic state, however, exhibits less sagging of the belly region compared with that reported in [67] because the material model used in this study includes the exponential stiffening under strain.”