Boundary Method Research Articles

Alternate method for resolving particle collisions in PRS of freely evolving particle suspensions using IBM

Particle Resolved simulations using the Immersed Boundary Method (IBM) are performed for freely evolving sphere suspensions in the Reynolds number range of [10, 300], solid volume fraction (φ) of [0.1, 0.4] with solid to fluid density ratio of 2, 10 and 100. Collisions between particles are initiated at an inter-particle buffer distance and solved between subsequent fluid time steps using a soft sphere model. Guidelines for permissible buffer distances are developed as a function of solid fraction. Viscous damping effects in the unresolved thin lubrication layer between particles near collision is modeled using a wet coefficient of restitution. Finally, a new correlation for particle fluctuating velocities is proposed and the predicted drag force is compared to previously proposed drag correlations.

A unified-field monolithic fictitious domain-finite element method for fluid-structure-contact interactions and applications to deterministic lateral displacement problems

Based upon two overlapped, body-unfitted meshes, a type of unified-field monolithic fictitious domain-finite element method (UFMFD-FEM) is developed in this paper for moving interface problems of dynamic fluid-structure interactions (FSI), which is accompanied with high-contrast physical coefficients across the interface and with contacting collisions between the structure and fluidic channel wall in the immersed FSI case. In particular, the proposed novel numerical method consists of a monolithic, stabilized mixed finite element method within the frame of fictitious domain/immersed boundary method (FD/IBM) for generic fluid-structure-contact interaction (FSCI) problems in the Eulerian–updated Lagrangian description, while involving the no-slip type of interface conditions on the fluid-structure interface, and the repulsive contact force/stress on the structural surface when the immersed structure contacts the fluidic channel wall. The developed UFMFD-FEM for FSI/FSCI problems can deal with the structural motion with large rotational and translational displacements and/or large deformation in an accurate and efficient fashion, which is first validated by two benchmark FSI problems and one FSCI model problem, then by experimental results of a realistic FSCI scenario – the microfluidic deterministic lateral displacement (DLD) problem that is applied to isolate circulating tumor cells (CTCs) from blood cells in the blood fluid through a cascaded filter DLD microchip in practice, where a particulate fluid with the pillar obstacles effect in the fluidic channel, i.e., the effects of fluid-structure interaction and structure collision, play significant roles to sort particles (cells) of different sizes with tilted pillar arrays. The developed unified-field, monolithic fictitious domain-based mixed finite element method can be seamlessly extended to more sophisticated, high dimensional FSCI problems with contacting collisions between the moving elastic structure and fluidic channel wall.

An eigenvalue stabilization technique for immersed boundary finite element methods in explicit dynamics

The application of immersed boundary methods in static analyses is often impeded by poorly cut elements (small cut elements problem), leading to ill-conditioned linear systems of equations and stability problems. While these concerns may not be paramount in explicit dynamics, a substantial reduction in the critical time step size based on the smallest volume fraction χ of a cut element is observed. This reduction can be so drastic that it renders explicit time integration schemes impractical. To tackle this challenge, we propose the use of a dedicated eigenvalue stabilization (EVS) technique.The EVS-technique serves a dual purpose. Beyond merely improving the condition number of system matrices, it plays a pivotal role in extending the critical time increment, effectively broadening the stability region in explicit dynamics. As a result, our approach enables robust and efficient analyses of high-frequency transient problems using immersed boundary methods. A key advantage of the stabilization method lies in the fact that only element-level operations are required.This is accomplished by computing all eigenvalues of the element matrices and subsequently introducing a stabilization term that mitigates the adverse effects of cutting. Notably, the stabilization of the mass matrix Mc of cut elements – especially for high polynomial orders p of the shape functions – leads to a significant raise in the critical time step size Δtcr.To demonstrate the efficiency of our technique, we present two specifically selected dynamic benchmark examples related to wave propagation analysis, where an explicit time integration scheme must be employed to leverage the increase in the critical time step size.

Snap-through dynamics of buckled flexible filaments in a side-by-side configuration

The flow-induced snap-through dynamics of side-by-side buckled flexible filaments in a uniform flow were investigated using the penalty immersed boundary method. We systematically examined the effects of gap distance and bending rigidity on the filament's motion and energy harvesting performance. Four distinct modes were observed as we varied the aforementioned parameters: the dual equilibrium mode, the dual streamwise oscillation mode, the single snap-through oscillation (STO) mode, and the dual STO mode. We analyzed the corresponding wake patterns associated with each of these modes. A phase transition from out-of-phase to in-phase motion was observed at low gap distances and bending rigidities. At lower gap distances, the interaction between two filaments was pronounced, leading to a co-motion of the filaments and enhanced elastic energy. This interaction decreased as the gap distance increased. Filaments in the 2STO mode exhibited significantly higher strain energy compared to the other modes. The elastic energy was concentrated at the rear part of the filaments and increased with higher gap distances and bending rigidities. Considering both energy harvesting efficiency and space utilization rate, a gap distance equal to 1 exhibited the best performance.

Nonlinear coupled multi-physics field analysis of permanent magnet synchronous motor combining finite element analysis with optimized meshless method

Aiming at significant disadvantages of finite element analysis (FEA) performed in coupled multiphysics field calculation, including high computing cost and strong dependency on meshing quality. Taking a high-speed permanent magnet synchronous motor (P MSM) as an example, an approach combining FEA with optimized meshless method is proposed to solve the heat transfer problem. Firstly, electromagnetic losses under rated and 1.2 times overloaded operation conditions are calculated using FEA respectively. Secondly, three-dimensional FEA flow models considering the influence of viscosity varying with temperature are established. Thirdly, convective heat transfer coefficients are calculated as the boundary condition, after which the electromagnetic losses as heat sources are mapped to the threedimensional steady-state temperature field calculations using FEA and conventional meshless method respectively. Applying the above two methods, a singular boundary method (SBM) is employed to replace the temporal derivative term of the transient calculation equation. Finally, to mitigate the illconditioned matrix appearing in the conventional meshless method coupled with FEA, an optimized meshless method is proposed to recalculate the heat transfer equation. After that, the calculation results of the above methods are compared with experimental results. This research is beneficial for the multiphysical coupling analysis of electrical equipment with complex structures considering nonlinear factors.

Pressure boundary conditions for immersed-boundary methods

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 forcing functions in the momentum equations, which in the case of fractional step methods may be problematic due to: i) creation of slip-errors resulting from the lack of explicitly enforcing boundary conditions on the (pseudo-)pressure on the immersed body; ii) coupling of the solution in the fluid and solid domains via the Poisson equation. Examples of fractional-step formulations that simultaneously enforce velocity and pressure boundary conditions have also been developed, but in most cases the standard Poisson equation is replaced by a more complex system which requires expensive iterative solvers. In this work we propose a new formulation to enforce appropriate boundary conditions on the pseudo-pressure as part of a fractional-step approach. The overall treatment is inspired by the ghost-fluid method typically utilized in two-phase flows. The main advantage of the algorithm is that a standard Poisson equation is solved, with all the modifications needed to enforce the boundary conditions being incorporated within the right-hand side. As a result, fast solvers based on trigonometric transformations can be utilized. We demonstrate the accuracy and robustness of the formulation for a series of problems with increasing complexity.

A hybrid lattice Boltzmann/immersed boundary method/finite-difference model for thermal fluid-solid interactions

Particulate flows are frequently observed in both industrial and natural environments, and their simulation becomes particularly challenging when heat transfer is involved. This study introduces a hybrid numerical approach, combining the lattice Boltzmann Method (LBM), Immersed Boundary Method (IBM), and Finite Difference (FD) energy solver to alleviate the limitations observed in double distributed lattice Boltzmann methods and classical Computational Fluid Dynamics (CFD). The model incorporates an enhanced Hermite polynomial-based central moments collision operator. This enhancement boosts stability and overcomes the Galilean-invariant issues observed in classical LBM. For heat transfer, a Finite-Difference technique is employed for resolving the energy equation, discretizing the advection term through a Weighted Essentially Non-Oscillatory (WENO) approach. The Boussinesq approximation handles buoyancy forces, while the direct-forcing IBM manages fluid-particle interaction. Validation across various test cases confirms the model's accuracy, showcasing its ability to account for variations in thermal properties like specific heat capacity Cp over a wide range. The model is further utilized to investigate a reactor containing 300 catalyst particles. In summary, this hybrid methodology is found to be a promising tool for comprehensively studying and designing particle-laden systems with thermal effects.

Prismatic-element SBPML coupled with SBFEM for 3D infinite transient wave problems

In this paper, an enhanced prismatic-element scaled boundary perfectly matched layer (SBPML) is developed, which is a novel time-domain artificial boundary method for 3D infinite wave problems. The SBPML permits the utilization of an artificial boundary with general geometry and can consider planar physical surfaces and interfaces extending to infinity. Moreover, this enhancement enables the seamless integration with surface meshes of arbitrary polygonal faces (such as triangles, quadrangles, pentagons, heptagons, octagons, etc.) at the truncation boundaries. The interior domain can be modelled by polyhedrons formulated by the scaled boundary finite element method (SBFEM). The geometric shape of the SBPML elements in the proposed method, within the local coordinate system, takes the form of a regular prism with regular polygonal top and bottom faces. Consequently, it is referred to as the Prismatic-element SBPML. Local scaled boundary coordinates based on the polygonal shape function are firstly introduced into the truncated infinite domain to describe its general geometry properties and provide the coupled capabilities with arbitrary polygonal face meshes at the truncation boundaries of numerical models. Then, a complex stretching function from PML is applied to radial direction of the local scaled boundary coordinates to map the physical space onto the complex space, resulting in a SBPML domain. Upon spatial discretization, the proposed method is formulated using a 2nd-order mixed displacement-stress unsplit-field formulation, allowing seamless coupling with FEM and SBFEM originally designed for the interior computational domain. Finally, three benchmark examples of wave propagation problems in unbounded domains and two soil-structure interaction problems of engineering problems are presented to demonstrate the accuracy and robustness of the Prismatic-element SBPML.

Hemodynamic Characteristics of Tortuous Microvessels Using High-Fidelity Red Blood Cell Resolved Simulations

Introduction: Tortuous microvessels are characteristic of microvascular remodeling associated with numerous physiological and pathological scenarios. These vessels have unique morphology compared to straight vessels, the latter being the subject of extensive flow modeling studies over the past few decades. Three-dimensional hemodynamics in tortuous microvessels influenced by red blood cell (RBCs), however, remain largely unknown and important questions remain. Is blood viscosity influenced by vessel tortuosity? Do RBC flow dynamics cause localized hematocrit variations in tortuous vessels? How do these dynamics affect wall shear stress patterns and the near-wall cell-free layer? Previous work has connected physiological function to tortuosity1, while other recent work has shown how RBC dynamics and vessel complexity can influence hemodynamics2. Such findings drive our hypothesis that unique hemodynamic characteristics exist in tortuous microvessels compared to straight vessels. Revealing such differences and answering the above questions requires 3D RBC-resolved simulations. The objective of this work is to investigate the hemodynamic characteristics of tortuous microvessels using high-fidelity red blood cell (RBC) resolved simulations and real image data. Methods: High fidelity RBC resolved simulations were performed using a 3D immersed boundary method (IBM) based fluid dynamic solver3. A tortuous microvessel is constructed in 3D based on imaging of a rat mesenteric microvascular network post angiogenic remodeling. The diameter and length of the vessel are 20 μm and 930 μm, respectively. Simulations were performed spanning a range of physiological shear rates (SR) and overall hematocrit levels (Ht). Output simulation data is used to parametrically quantify characteristics of apparent viscosity, local hematocrit variations, time-averaged wall shear stress (TAWSS) and cell free layer (CFL) patterns due to vessel tortuosity. Data and Results: The findings show how curvature can increase apparent viscosity to different degrees based on overall Ht & SR (max 236% increase), with local variations occurring over the vessel length at sites of curvature changes (max 2.25cP change). Because of RBC flow patterns, local variations in tube hematocrit are found to occur which result in local curvature-dependent variations in the Fahraeus effect. We further characterize dependencies of the CFL and TAWSS on Ht & SR and resultant lengthwise 3D spatial variations along the vessel, and demonstrate correlation patterns between these two quantities as influenced by tortuosity. Conclusions: New findings from this work reveal significant dependency of hemodynamic parameters and spatial variations on vessel tortuosity. The results provide new information to better understand the role of vessel tortuosity in physiological and pathological processes, as well as help improve reduced-order models. NSF CBET 2309559, NIH R21HL159501, and Expanse at the San Diego Supercomputer Center per NSF Accelerate Award BIO230073. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

A numerical modeling study on the impact of particle concentration on the particle sorting in spiral channels

This work investigates the influence of concentration on the separation of microparticles in spiral microchannels. Using numerical modeling, we study the impact of the particle concentration on fluid flow pattern, particle trajectory, focusing resolution, and focusing time. Immersed boundary method and a numerical solver are developed in the OpenFOAM framework for modeling of particle motion. Modeling for different particle concentration in both rectangular and trapezoidal spiral channels is conducted to elucidate the particle focusing and separation efficiency in the spiral channels with a large number of particles. The detailed numerical modeling results clarify the configuration of Dean flow with multiple particles, the interaction within the particle cloud, and the impact of particle concentration on the focusing time and sorting process.

A weighted shifted boundary method for immersed moving boundary simulations of Stokes' flow

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 surrogate domain is constructed so as to avoid cut cells and the associated problematic implementation and numerical integration issues. Accuracy is maintained by modifying the original boundary conditions using Taylor expansions: hence the name of the method, that shifts the location and values of the boundary conditions. In this article, we extend the SBM to the simulation of incompressible Stokes flow, by appropriately weighting its variational form with the elemental volume fraction of active fluid. This approach allows to drastically reduce spurious pressure oscillations in time, which are produced if the total volume of active fluid were to change abruptly over a time step. The proposed Weighted SBM (W-SBM) exactly preserves states of hydrostatic equilibrium, and induces small mass and momentum conservation errors, which converge as the grid is refined. This is in analogy to cutFEMs and related unfitted approaches, which rely on an affine representation of cut boundaries. We demonstrate the robustness and accuracy of the proposed method with an extensive suite of two-dimensional tests.

A Fourier spectral immersed boundary method with exact translation invariance, improved boundary resolution, and a divergence-free velocity field

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 immersed boundary. The new Fourier spectral immersed boundary (FSIB) method gives improved boundary resolution in comparison to the standard IB method. The interpolated velocity field, in which the boundary moves, is analytically divergence-free. The FSIB method is gridless and has the meritorious properties of volume conservation, exact translation invariance, conservation of momentum, and conservation of energy. We verify these advantages of the FSIB method numerically both for the Stokes equations and for the Navier-Stokes equations in both two and three space dimensions. The FSIB method converges faster than the IB method. In particular, we observe second-order convergence in various problems for the Navier-Stokes equations in three dimensions. The FSIB method is also computationally efficient with complexity of O(N3log⁡(N)) per time step for N3 Fourier modes in three dimensions.

A Time-Domain Wavenumber Integration Model for Underwater Acoustics Based on the High-Order Finite Difference Method

Simulating the acoustic field excited by pulse sound sources holds significant practical value in computational ocean acoustics. Two primary methods exist for modeling underwater acoustic propagation in the time domain: the Fourier synthesis technique based on frequency decomposition and the time-domain underwater acoustic propagation model (TD-UAPM). TD-UAPMs solve the wave equation in the time domain without requiring frequency decomposition, providing a more intuitive explanation of the physical process of sound energy propagation over time. However, time-stepping numerical methods can accumulate numerical errors, making it crucial to improve the algorithm’s accuracy for TD-UAPMs. Herein, the time-domain wavenumber integration model SPARC was improved by replacing the second-order finite element method (FEM) with the high-order accuracy finite difference method (FDM). Furthermore, the matched interface and boundary (MIB) method was used to process the seabed more accurately. The improved model was validated using three classic underwater acoustic benchmarks. By comparing the acoustic solutions obtained using the FDM and the FEM, it is evident that the improved model requires fewer grid points while maintaining the same level of accuracy, leading to lower computational costs and faster processing compared to the original model.

Hydrodynamic performance analysis of formations of dual three-dimensional undulating fins

The work seeks to understand the hydrodynamic performance and interaction mechanisms of double-fin formations. A high-resolution numerical technique based on the constraint immersed boundary method is used for simulating the 3D double-fin system. Comprehensive analysis is carried out, focusing on the hydrodynamic performance of formations with various arrangements, phase differences, and spatial distances. The result shows that the side-by-side formation can suppress the thrust of the fins while reducing energy consumption. The tandem formation notably enhances the thrust for the fin positioned at the rear, albeit at the cost of increased energy consumption. In the tandem formation with a small spacing, the following fin can obtain a thrust increase of 28% and an efficiency increase of 10%, independent of the phase difference. The thrust enhancement in the tandem formation is related to the suction-based propulsion mechanism induced by hydrodynamic interactions. However, the interaction mechanism between the two side-by-side fins resembles the so-called channelling effect. The unilateral channel flow perturbs the pressure equilibrium on either side of the fin, potentially imposing additional resistance on the undulating fin, with effects depending on the phase difference. The study offers new insights into understanding the collective behaviours of undulating fins.

A Novel Cell-Based Adaptive Cartesian Grid Approach for Complex Flow Simulations

As the need for handling complex geometries in computational fluid dynamics (CFD) grows, efficient and accurate mesh generation techniques become paramount. This study presents an adaptive mesh refinement (AMR) technology based on cell-based Cartesian grids, employing a distance-weighted least squares interpolation for finite difference discretization and utilizing immersed boundary methods for wall boundaries. This facilitates effective management of both transient and steady flow problems. Validation through supersonic flow over a forward-facing step, subsonic flow around a high Reynolds number NHLP airfoil, and supersonic flow past a sphere demonstrated AMR’s efficacy in capturing essential flow characteristics while wisely refining and coarsening meshes, thus optimizing resource utilization without compromising accuracy. Importantly, AMR simplified the capture of complex flows, obviating manual mesh densification and significantly improving the efficiency and reliability of CFD simulations.

Rigorous benchmarking of an iterative IBM solver by comparison to body-fitted mesh results

This study addresses the validation challenges of Immersed Boundary Method (IBM) solvers by proposing a consistent benchmarking approach. A temporally second-order Arbitrary Lagrangian–Eulerian (ALE) solver implemented in OpenFOAM is verified against lid-driven cavity flow and flow past static and oscillating cylinders. It then serves as the underlying fluid flow solver for a fully implicit diffusive direct forcing IBM solver that achieves temporal second-order accuracy, verified by the static and oscillating cylinder cases. Leveraging the shared numerical framework, the IBM solver is rigorously validated against ALE using identical settings, parameters, and nearly identical grids across twenty test cases, including stationary cylinder flow (Re = 40, 100, 185), oscillating cylinder in quiescent flow (Re = 100, KC = 5), and transversely oscillating cylinders with varying amplitudes and frequencies (16 cases in total). The IBM solver demonstrates robustness (CFL up to 8) and accuracy over a wide Reynolds number range, with relative drag coefficient errors below 7% for all considered cases. Incorporating body force correction, which reduces slip errors at negligible added computational cost, drastically improves accuracy. Proper Rhie–Chow momentum interpolation, including body forces, is critical in the adopted collocated finite volume method. For unsteady problems, the computational cost is greatly reduced without compromising accuracy by using CFL≈1.5−2 with only two outer iterations. The proposed benchmarking framework can be easily used for validation of other IBM approaches and thus potentially help to advance the state of IBM.

Slamming Characteristics Due to the Special Shape of New Sandglass-Type Model in Waves by Comparing with Cylindrical Model

For the new sandglass-type FPSO, the unique shape of its floating body with oblique side and external expansion can significantly improve the motion performance, but meanwhile may result in specific slamming characteristics in waves. On this basis, this paper establishes a CFD method including numerical wave-tank technique based on the Open FOAM platform. Therein, the velocity-inlet boundary method and the active absorption method are applied for numerical wave-making and wave-absorption. Compared with experimental results, the numerical method can be validated to be accurate enough to simulate wave slamming on floating ocean platforms. Then, the specific slamming phenomena on the sandglass-type floating body under a classic long wave can be investigated by comparing with the cylindrical model, including nonlinear wave rollover and breaking, water cushion, rooster-tail wave, side wave, water tongue, and so on. The mechanism of these phenomena and their effects on slamming pressure are studied. The essences of typical peaks in the time-history curve of the slamming pressure are mainly discussed. More interestingly, the main peak can be found to be related to the small peak due the amount of the broken water and the thickness of the water cushion. Finally, the slamming characteristics of the sandglass-type model in a classic short-wave condition are comparatively discussed.

Enhanced fully resolved CFD-DEM-PBFM simulation of non-spherical particle–fluid interactions during hydraulic collection

The interactions between non-spherical particles and fluids are commonplace in both nature and engineering applications, such as deep-sea nodules hydraulic collection. However, accurately simulating granular particles with non-spherical shapes and gaining a deep understanding of the intricate mechanisms involved in fluid–particle interactions still pose significant challenges. In this study, the superquadric model and the Gaussian curvature model are introduced in the Discrete Element Method to describe particle shapes and characterize their nonlinear contact behavior, respectively. Simultaneously, the Fictitious Domain-Immersed Boundary Method (FD-IBM) and the Particle Boundary Field Method (PBFM) are employed to enhance the stability and accuracy of numerical simulations. Building upon these advancements, an extended resolved CFD-DEM-PBFM method is developed. The validation and superiority of this resolved CFD-DEM-PBFM method are rigorously verified by comparing its results with the experimental and other research results across various scenarios, including non-spherical particle collision and packing, particle settling, drafting-kissing-tumbling test, and flow around non-spherical particles. Subsequently, the application of our novel model has been further conducted by a case study that simulates the hydraulic collection of nodules with different aspect ratios l/d. Concurrently, the influences of the nodule shapes on the hydraulic collection mechanism of the hydraulic collection are unveiled in terms of suction forces, trajectory of the particle, and flow field characteristics. Our findings demonstrate that the extended resolved CFD-DEM-PBFM method excels at accurately characterizing multiphase interaction mechanisms at both macro and micro scales, presenting considerable advantages in simulating fluid-particle systems involving non-spherical particles.

Shape optimization of embedded solids using implicit Vertex-Morphing

One of the biggest challenges in optimizing the shape of complex solids is the requirement to maintain a reasonable mesh quality not only at the boundary but also for the bulk discretization of the interior. Thus, additional regularization and, in many cases, re-meshing of the structure during the iterative process is unavoidable with a Lagrangian description. By tracking the shape update using an Eulerian representation, embedded boundary methods are a promising technique for eliminating mesh distortion problems.This work consistently combines the unique features of implicit Vertex-Morphing and embedded boundary methods, facilitating the node-based shape optimization of solids with industrial complexity. One of the crucial elements for solving the primal problem on a fixed background grid is an efficient and robust quadrature scheme. To this end, we incorporate the open-source C++ framework QuESo (https://github.com/manuelmessmer/QuESo) developed for the numerical integration of arbitrarily complex embedded solids defined by oriented boundary meshes, e.g., in STereoLithography (STL) format. Meanwhile, applying the Helmholtz/Sobolev-based (implicit) filter to the vertices of the embedded boundary mesh not only exploits the extensive design space of node-based optimization but also ensures robust control over the feature size. To realize the above methodology, this work introduces a novel sensitivity analysis that yields mesh-independent shape gradients with respect to the immersed boundary. Through a specific sensitivity weighting, we recover a continuous gradient field from discrete values calculated at the nodes of the background grid. In addition, the presented workflow ensures robust enforcement of challenging geometrical constraints, including minimum wall thicknesses and design space limitations.We critically assess our approach with benchmarks and structures of industrial relevance. In all examples, trivariate B-Spline bases span the background grid, providing highly accurate finite element solutions and shape sensitivities at every iteration. Moreover, the elimination of mesh distortion problems enables a successful termination at the local optimum, even for large shape modifications.

A flow-reconstruction based approach for the computation of hydrodynamic stresses on immersed body surface

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 gradient information on the immersed boundary, we employ a model to reconstruct the near-boundary fluid flow along the surface normal direction. Different from most existing flow reconstruction models in diffuse-interface IBMs based on the boundary layer approximation, we propose a new reconstruction model relying only on the non-slip velocity and local flow information. With this improvement, the present reconstruction model is theoretically applicable to fluid flows with intermediate Reynolds numbers (with the existence of a laminar boundary layer) and low Reynolds numbers (in the absence of a boundary layer). To examine the validity of the present reconstruction model, we conduct a series of simulations, including the uniform flow past a fixed body and the settling of a rigid body in a quiescent fluid. It is demonstrated that the present reconstruction model has a better performance than existing models in predicting hydrodynamic stresses on the immersed boundary within a wide range of Reynolds numbers from O(1) to O(100). The capability and robustness of the proposed model demonstrate its potential to address fluid-solid interaction problems with a-priori unknown or time-varying Reynolds numbers, such as fully resolved simulations of particle laden flows.