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The Shifted Boundary Method (SBM) belongs to the class of unfitted (or immersed, or embedded) finite element methods, and relies on reformulating the original boundary value problem over a surrogate (approximate) computational domain. The ...

• The Weighted Shifted Boundary Method (W-SBM) is extended to Stokes flow with moving boundaries.
• New no-slip conditions are developed, with optimal accuracy.
• Spurious pressure oscillations in time are drastically reduced by volume ...

Immersed boundary methods have seen an enormous increase in popularity over the past two decades, especially for problems involving complex moving/deforming boundaries. In most cases, the boundary conditions on the immersed body are enforced via ...

• Most fractional step implementations of IB methods do not explicitly enforce boundary conditions on the pressure.
• Lack of enforcement of boundary conditions to the pressure results to slip-errors on the body.
• The new formulation we ...

This paper introduces a new immersed boundary (IB) method for viscous incompressible flow, based on a Fourier spectral method for the fluid solver and on the nonuniform fast Fourier transform (NUFFT) algorithm for coupling the fluid with the ...

• The FSIB method is gridless and has exact translation invariance.
• A divergence-free interpolated velocity field that conserves volume.
• Equivalent to the use of a new ‘sinc’ kernel in the framework of IB method.
• Improved ...

In this paper we propose an improved three-dimensional immersed boundary method coupled with a finite-difference code to simulate self-propelled phoretic particles in viscous incompressible flows. We focus on the phenomenon of diffusiophoresis ...

• We correct immersed boundary terms through the addition of forces from previous time steps.
• The approach departs from traditional methods that rely solely on instantaneous forces, enhancing simulation accuracy.
• The study presents a ...

This study focuses on obtaining reliable hydrodynamic stresses on the surface of rigid bodies in the simulation of fluid-solid interactions using the diffuse-interface immersed boundary method (IBM). In order to obtain the pressure and velocity ...

In this work, the immersed boundary method with time filter and scalar auxiliary variable techniques is studied to solve the fluid–structure interaction problems. For the fluid flow, we first use the backward Euler differentiation formula in ...

We present and analyze a series of benchmark tests regarding the application of the immersed boundary (IB) method to viscoelastic flows through and around non-trivial, stationary geometries. The IB method is widely used to simulate biological ...

• The Immersed Boundary method is applied to viscoelastic flows around non-trivial, stationary geometries.
• Computational results are compared to previous numerical benchmarks and macrorheology experiments.
• Choices of relative ...

In this paper, a new hybrid numerical approach is presented that couples “ghost cell” based immersed boundary (IB) method with the finite volume lattice Boltzmann method (FVLBM). In the implementation process, the grid cells are classified into ...

The projection immersed boundary method calculates boundary forces (i.e., surface stresses) from velocity constraints without introducing additional timestep restrictions. However, the projection method generally fails to produce boundary forces ...

• Proposed a Tikhonov regularized projection immersed boundary method.
• Accurately computed body forces, eliminating spurious oscillations.
• Demonstrated convergence of body forces with test problems.
• Validated applicability to FSI ...

In this paper, we present an efficient and stable fractional-step 2D immersed boundary (IB) method for solving the interaction problems between bulk fluid and elastic interface, in particular, when the fluid inertia and the interfacial ...

• An efficient and stable fractional-step immersed boundary (IB) method is developed.

The problem of incompressible flow simulation around rigid bodies of arbitrary shape is considered. The LS-STAG immersed boundary method is used for its numerical solving. This method is based on the accurate discretization of the governing ...

Embedded (or immersed) boundary methods (EBMs) for CFD and fluid-structure interaction (FSI) are attractive for aerodynamic optimization problems characterized by large shape deformations and surface topology changes. At each iteration, they ...

• Analytical sensitivities of a differentiable embedded boundary method (EBM).
• Application of an EBM to gradient-based shape optimization problems.
• Realistic shape design problems dominated by large shape and topology changes.

In this study, we present a parallel immersed boundary strategy that uses Nitsche's method (noted NIB) to weakly impose on a given fluid the boundary conditions associated with a solid of arbitrary shape and motion. Specific details of ...

• An immersed boundary method is formulated and validated with experimental data.

A numerical strategy based on an immersed boundary method (IBM) is presented for performing high-fidelity simulation of thermal hydraulics while including Conjugate Heat Transfer (CHT). The well documented pipe flow is considered which,...

• Original IBM to impose Neumann BC when wall-geometry and mesh-grid are disconnected.

We propose an immersed boundary scheme for the numerical resolution of the Complete Electrode Model in Electrical Impedance Tomography, that we use as a main ingredient in the resolution of inverse problems in medical imaging. Such method allows ...

• The resolution of the Complete Electrode Model in Electrical Impedance Tomography by immersed boundary methods is assessed.
• Several equivalent formulations of the CEM are considered.
• A first order finite difference Immersed ...

We present a novel framework to deal with static and moving immersed boundaries (IB) based on volume-filtering. In this strategy, called Volume-Filtering Immersed Boundary (VFIB) method, transport equations are derived by filtering the ...

• We present a new framework for immersed boundary methods free from ad-hoc fixes.

For the thermal–fluid–structure interaction (TFSI) problems with moving boundaries, the original implicit boundary condition-enforced immersed boundary method (IBM) by Wang et al. [1] has to generate a large correlation matrix and ...

• An explicit boundary condition-enforced immersed boundary method is proposed.
• ...

Future advanced aero-engine features highly complex internal flow mechanisms, such as small gap blade row interactions and coupled fluid-structure interactions. Simulating these is challenging for convectional body-fitted computation ...

This paper develops a tree-topological local mesh refinement (TLMR) method on Cartesian grids for the simulation of bio-inspired flow with multiple moving objects. The TLMR nests refinement mesh blocks of structured grids to the target regions ...

• We develop a Cartesian-grid-based mesh refinement method for solving incompressible Navier-Stokes equations.
• The method uses tree-topological mesh refinement blocks wherever high-resolution meshes are needed around immersed bodies.

We present a Graphical Processing Unit (GPU) accelerated sharp interface Immersed Boundary (IB) method that can be applied to versatile geometries on a staggered Cartesian grid. The current IB solver predicts the flow around arbitrary surfaces of ...

• A field extension based sharp IB method for bluff bodies and thin surfaces.
• Improved accuracy near sharp edges using multi-directional forcing.
• A surface tracking algorithm based on modified signed distance approach.
• GPU ...