Numerical methods are proposed for the nonlinear Stokes-Biot system modeling interaction of a free fluid with a poroelastic structure. We discuss time discretization and decoupling schemes that allow the fluid and the poroelastic structure computed independently using a common stress force along the interface. The coupled system of nonlinear Stokes and Biot is formulated as a least-squares problem with constraints, where the objective functional measures violation of some interface conditions. The local constraints, the Stokes and Biot models, are discretized in time using second-order schemes. Computational algorithms for the least-squares problems are discussed and numerical results are provided to compare the accuracy and efficiency of the algorithms.
K E Y W O R D Sdomain decomposition, fluid structure interaction, poroelasticity
INTRODUCTIONThe interaction of a fluid with a poroelastic material is of great importance in many engineering and biological applications. In such applications, a free fluid interacts with a deformable porous medium, where the structure is poroelastic, accounting for both the effects of porosity and elasticity. These interactions can be found in many applications such as reservoir engineering, groundwater flow, blood flow through vessels, and more. 1-4 Specifically for a blood flow, the interaction between blood and the arteries, as well as the effect of a blood clot, is a fluid-poroelastic system. 2 Other related applications are fluid flows through aquifers, bodies of permeable rock that can contain or transmit groundwater, where fluids such as water or oil flow through materials such as clay, sand, or sandstone. 3,5 There are a wide variety of solution algorithms proposed for fluid-structure interaction (FSI) problems of the Navier-Stokes coupled with the linear elasticity, but each is limited by computational complexity and stability. [6][7][8] While studies on the system of fluid and elastic structure have been active for the last 20 years, interaction of fluid flows with a poroelastic structure has received less attention and there are relatively a few numerical results reported for such problems. FSI problems involving an incompressible fluid and a poroelastic structure are often represented by the coupled Navier-Stokes and Biot (or Stokes-Biot) system with conditions on the interface between fluid and structure subdomains. A monolithic approach is computationally complex as it requires solving a large linear system; therefore, one needs the development of efficient and appropriate preconditioners for the discretized linear system. Ambartsumyan et al 9 studied a monolithic scheme for the Stokes equations coupled with the quasi-static Biot system, based on the Lagrange multiplier method. The proposed monolithic scheme was analyzed for stability and error estimation. Recently, a nonlinear Stokes-Biot system was considered for the analysis of well-posedness in Reference 10, Int J Numer Meth Fluids. 2020;92:687-702.wileyonlinelibrary.com/journal/fld Consider the domain of a fluid-...