Computational Time Step Research Articles

A coupled scaled boundary finite element and phase-field algorithm for seismic loading

Seismic-induced damage, integral to the safety evaluations of major engineering projects, persists as a key focus of research worldwide. Based on the Scaled Boundary Finite Element Method (SBFEM) and the Phase-Field Method (PFM), a coupled algorithm tailored for reciprocal loading was introduced in this paper, integrating strategies including "closure constraints," "numerical threshold strategy," and "subdomain block integration." Adopting object-oriented principles, a universal coupling solution framework has been built and seamlessly embedded within GEODYNA, a self-developed finite element software system. The accuracy was validated through rigorous benchmark tests. The entire process of crack initiation, propagation, and dynamic opening-closing cycles in the Koyna concrete gravity dam was reproduced. Furthermore, the effect of mesh size and computational timestep on the structural seismic response, crack localization, and the extent of damage in the dam were explored. The outcomes demonstrated that the SBFEM-PFM coupling algorithm performs effectively and meets the engineering precision criteria for seismic evaluations and reinforcement analyses of crucial structures.

Experimental and numerical investigation on detection of BVID in CFRP composite plates using vibro-acoustic modulation

ABSTRACT Carbon fibre reinforced plastic (CFRP) composite has gained popularity due to the advantages such as its high strength-to-weight ratio and high corrosion resistance, but susceptibility to barely visible impact damage limits their use in engineering. This study experimentally and numerically investigates the detection of BVID in CFRP composite plates using Vibro-acoustic modulation (VAM) technique. An experimental system of VAM was constructed for measuring sidebands induced by the nonlinear effects of BVID. An integrated finite element (FE) model is developed to further explore the nonlinear interaction between the BVID, low-frequency pump, and high-frequency probe waves. To address this issue of the mesh size and computational time step mismatch caused by the large difference in frequency between the pump and probe waves, a regionally refined mesh was employed at the BVID region. Furthermore, the effects of BVID’s size and depth on the modulation were discussed. Through the Hilbert-Huang Transform (HHT), the amplitude modulation (AM) and frequency modulation (FM) indexes were extracted from the VAM responses to quantitatively characterise the impact damages. The results demonstrate that the MIA index increases steadily with the exciting voltage and damage degree, making it a suitable indicator to accurately assess the impact damage in CFRP composites.

Novel barostat implementation for molecular dynamics.

We propose a novel implementation of the extended-dynamics equations for isothermal-isobaric ensemble in molecular dynamics, as the Martyna-Tobias-Klein thermostat and barostat. This method is suitable for systems with constraints and the Verlet-family integrators. Instead of iterations or the Trotter-expansion-based methods, both velocities and box sizes (scaling of bond lengths) are predicted. The algorithm begins with force calculation, requiring neither quarter nor half time steps, and necessitating iterations only inside SHAKE. Several tests demonstrate that the quality is comparable to other implementations. It is found that the formula relating the extended barostat mass to the characteristic time of volume fluctuations is inaccurate for condensed systems, which has consequences for the parameter setup. Emphasis is also put on the verification of the precise isothermal-isobaric ensemble and finite-size effects.

Enhanced physics‐informed neural networks for efficient modelling of hydrodynamics in river networks

AbstractThis article enhances the physics‐informed neural networks (PINNs) method to effectively model the hydrodynamics of real‐world river networks with irregular cross‐sections. First, we pre‐process hydraulic parameters to optimize training speed without compromising accuracy, achieving a 91.67% acceleration compared with traditional methods. To address the vanishing gradient problem, layer normalization is also incorporated into the architecture. We also introduce novel physical constraints—water level range and junction node equations—to ensure effective training convergence and enrich the model with additional physical insights. Two practical case studies using HEC‐RAS benchmarks demonstrate that our improved PINN method can predict river network hydrodynamics with less data and is less sensitive to time step size, allowing for longer computational time steps. Incorporating physical knowledge, our enhanced PINN methodology emerges as an efficient and promising avenue for modelling the complexities of hydrodynamic processes in natural river networks.

A robust algorithm for computational floating body dynamics.

We present a non-iterative algorithm, FloatStepper, for coupling the motion of a rigid body and an incompressible fluid in computational fluid dynamics (CFD) simulations. The purpose of the algorithm is to remove the so-called added mass instability problem, which may arise when a light, floating body interacts with a heavy fluid. The idea underlying the presented coupling method is to precede every computational time step by a series of prescribed probe body motions in which the fluid response is determined, thus revealing the decomposition of the net force and torque into two components: (i) an added mass contribution proportional to the instantaneous body acceleration and (ii) all other forces and torques. The algorithm is implemented and released as an open-source extension module to the widely used CFD toolbox, OpenFOAM, as an alternative to the existing body motion solvers. The accuracy of the algorithm is investigated with several single-phase and two-phase flow benchmark cases. The benchmarks demonstrate excellent stability properties, allowing simulations even with massless bodies. They also highlight aspects of the implementation, such as the mesh motion method, where it can be improved to further enhance the flexibility and predictive capabilities of the code.

Coupling of the immersed boundary and Fourier pseudo-spectral methods applied to solve fluid–structure interaction problems

The current manuscript addresses fluid–structure interaction (FSI) problems to the analysis of vortex-induced vibration (VIV), employing the methodology designated as IMERSPEC2D. The approach seamlessly integrates the Fourier pseudo-spectral method (FPSM) and the immersed boundary method (IBM) to solve the Navier–Stokes (NS) and continuity equations. Simultaneously, the effects of cylindrical structure, involving 1 and 2 degrees of freedom (d.o.f.) are simulated, by incorporating structural motion equations into NS via the IBM source term and implementing a two-way FSI algorithm. In the paper are presented the comparison of low and high-order temporal integration methods applied to solve the dynamic behavior of the structure and the dimensionless of the cylinder’s structural motion equations, resulting in an increase in computational time step from 1E(-9\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$-9$$\\end{document}) to 1E(-3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$-3$$\\end{document}). Validation results to refined mesh simulations include the accurate representation of the lock-in phenomenon to simulations of 1 d.o.f. obtaining the range between reduced velocity 5.456 and 5.568 and the maximal amplitude is 0.352. Notably, the eight-shape pattern of the 2 d.o.f. cylinder displacement is obtained and the formation of C2S wake patterns is achieved, as presented by other authors. In conclusion, the dimensionless approach reduces computational time, while the high-order both of IMERSPEC methodology and time advancement integration to FSI improve the results of the cylinder’s motion and alters distinct vortex shedding patterns in fluid dynamics.

A two-dimensional friction-decoupling method based on numerical integration method and momentum theorem

This article introduces a simplified Two-Dimensional Friction-Coupling Model (TDFC) designed for typical surface-to-surface contact friction systems in engineering structures. With the assumption of a constant friction force magnitude within each calculation time step, the alteration of the friction direction of TDFC within each calculation time step can be visualized as the rotation of a circular radius under horizontal bidirectional dynamic loads. This dynamic force analysis approach is referred to as the “Circular making”. It is noteworthy that the friction direction change in each calculation time step demonstrates unidirectional rotatability. Leveraging this rotatability and assuming uniform rotation, the momentum theorem accurately determines the direction of the plane friction acting on the TDFC model at the end of each calculation time step. This allows for the decoupled calculation of plane friction and precise response calculation of the TDFC model. The study verifies the reliability of theoretical assumptions, such as constant friction force magnitude and uniform rotation, with a time step of 0.01 s. Additionally, by introducing an equivalent spring effect to modify the TDFC model, it is observed that the modified TDFC effectively simulates the behavior of the Friction Pendulum Bearing (FPB) under horizontal bidirectional seismic loads. Compared to the ABAQUS finite element model of FPB, the modified TDFC model provides a more efficient approach for rapidly and accurately calculating the response of various FPB types under horizontal bidirectional seismic loads by adjusting parameter values of the modified TDFC model.

Adaptive Mesh Refinement for Trailing Vortices Generated by Propellers in Interaction with Slipstream Obstacles

The investigation of cavitating trailing vortices emerging from marine propellers is of great interest in the industry. With the help of computational fluid dynamics (CFD), studying the cavitating trailing vortices may be facilitated. However, limitations in computational power raise the necessity to execute numerical simulations as efficiently as possible. The time-efficient simulation of cavitating trailing vortices interacting with rigid bodies is especially challenging due to the continuous change of cavity locations. This study investigates the usability, capability, and practicability of automatic adaptive refinement at every calculation time step for transient Reynolds-averaged Navier–Stokes (RANS) and large eddy CFD simulations of the cavitating tip and hub vortices, utilizing the Schnerr–Sauer cavitation model, in the presence of a rudder located in the propeller slipstream and for an isolated propeller, with additional focus on the computational effort necessary for using high frequency updating adaptive mesh refinement (AMR). It is found that AMR is suitable for resolving cavities with relative motion to the propeller and in interaction with slipstream obstacles. However, the computation time is significantly increased, which renders this method useful only if a classic AMR is not possible due to geometrical limitations. Even in the cases that benefit from the automated AMR, numerical instabilities may lead to unphysical pressure fluctuations, which reduce the suitability of the method for the evaluation of underwater radiated noise.

A novel method for solving hydration heat release based on equivalent heat release theory

Current hydration heat release rate algorithms that consider the temperature history are based on the Arrhenius law and other hypothetical conditions. Nevertheless, reported research results have shown controversy regarding the values of Arrhenius law and other model parameters, potentially introducing errors in calculated results. Some studies have shown that adiabatic temperature rises at different placement temperatures can be expressed by a mathematical expression; thus, this study establishes a relational model for the hydration temperature rise rate of concrete structures under any temperature history. This study uses the hydration temperature rise rate of the adiabatic temperature rise test under equivalent conditions to directly obtain the hydration temperature rise rate for any temperature history. Except for special cases, the proposed algorithm does not rely on the Arrhenius law and other hypothetical conditions, thus avoiding errors caused by the associated assumptions. Additionally, this study utilizes an integration method to solve a problem in which a small calculation time step is required to guarantee the accuracy of the solution under the conventional finite element framework. Furthermore, an iterative algorithm is proposed to solve the problem in which the temperature at the end of the calculation time step must be used when the temperature history is considered. Examples show that the proposed method exhibits a high calculation precision and improves efficiency; and the maximum temperature difference between the calculated and measured values is only 0.085 °C.

Impacts of Uncontrolled Operator Splitting Methods on Parameter Identification, Prediction Uncertainty, and Subsurface Flux Representation in Conceptual Hydrological Models

AbstractThe proper numerical representation of physical processes in mechanistic hydrological models is essential to produce robust predictions. A common problem with numerical schemes in hydrological models is that multiple concurrent fluxes are calculated sequentially. Although the importance of errors introduced by inappropriate numerical schemes is well recognized in the literature, many hydrological models calculate concurrent fluxes sequentially. Here, two versions of the HYPE model are used to investigate the limitations of sequential calculations. A fourth order Gear‐Nordsieck solution of the continuous state‐space formulation of HYPE (I‐HYPE) is developed to provide a robust solution, and a fixed‐step implicit Euler scheme (IE‐HYPE) is implemented to provide a computationally efficient and robust approximation of the I‐HYPE simulations. In contrast to I‐HYPE, results show that the original HYPE and the sequential calculation implemented in the continuous state‐space formulation of HYPE (SQ‐HYPE) typically simulate no interflow when soil moisture levels exceed the field capacity. The discrepancy between SQ‐HYPE and I‐HYPE grows with the size of the computation time step, and this implies a compromised representation of flow paths by sequential schemes. IE‐HYPE provides responses comparable with I‐HYPE for both daily and hourly time steps. IE‐HYPE and SQ‐HYPE are compared in terms of their groundwater representation, parameter identifiability, and predictive skills for two catchments. The sequential models have larger groundwater contributions to flow than IE‐HYPE because the splitting errors in SQ‐HYPE limit the interflow flux. IE‐HYPE estimates of the groundwater flux are more consistent with literature values of groundwater contributions to flow for the basins studied.

Investigation of proper orthogonal decomposition for echo state networks

Echo State Networks (ESN) are a type of Recurrent Neural Network that yields promising results in representing time series and nonlinear dynamic systems. Although they are equipped with a very efficient training procedure, Reservoir Computing strategies, such as the ESN, require high-order networks, i.e., many neurons, resulting in a large number of states that are magnitudes higher than the number of model inputs and outputs. A large number of states not only makes the time-step computation more costly but also may pose robustness issues, especially when applying ESNs to problems such as Model Predictive Control (MPC) and other optimal control problems. One way to circumvent this complexity issue is through Model Order Reduction strategies such as the Proper Orthogonal Decomposition (POD) and its variants (POD-DEIM), whereby we find an equivalent lower order representation to an already trained high dimension ESN. To this end, this work aims to investigate and analyze the performance of POD methods in Echo State Networks, evaluating their effectiveness through the Memory Capacity (MC) of the POD-reduced network compared to the original (full-order) ESN. We also perform experiments on two numerical case studies: a NARMA10 difference equation and an oil platform containing two wells and one riser. The results show that there is little loss of performance comparing the original ESN to a POD-reduced counterpart and that the performance of a POD-reduced ESN tends to be superior to a normal ESN of the same size. Also, the POD-reduced network achieves speedups of around 80% compared to the original ESN.

An iterative method for the thermally coupled incompressible magnetohydrodynamics equations at high parameter

We design an iterative method based on linearization approach for the thermally coupled stationary incompressible magnetohydrodynamics equations at high physical parameters. The iterative method includes solving the considered equations by the linearization approach and applying the error correction strategy to reduce the iterative error arising from the linearization approach for solving the nonlinear equations. The iterative method not only can improve computational capability for solving the considered equations at high physical parameters but also can save computational time and iterative step. Moreover, we prove the stability of the iterative method and derive the iterative error estimates. Finally, some numerical tests are implemented to illustrate the efficiency of the presented method.

A high efficiency Lie derivative algorithm for the nonautonomous nonlinear systems

Numerical procedure plays a key role in tackling the solutions of nonlinear dynamical systems. With the advent of the age of big data and high-power computing, developing efficient and fast numerical algorithms is an urgent task. This paper extends the Lie derivative discretization algorithm to the nonautonomous nonlinear systems and investigates the numerical solutions of the systems. The periodic solutions of three different classical nonlinear systems are calculated, and the results are compared to those values calculated from the Runge–Kutta fourth-order algorithm, which demonstrated that the Lie derivative algorithm has the advantages of large time step and short computation time.

An exa-scale high-performance molecular dynamics simulation program: MODYLAS.

A new version of the highly parallelized general-purpose molecular dynamics (MD) simulation program MODYLAS with high performance on the Fugaku computer was developed. A benchmark test using Fugaku indicated highly efficient communication, single instruction, multiple data (SIMD) processing, and on-cache arithmetic operations. The system's performance deteriorated only slightly, even under high parallelization. In particular, a newly developed minimum transferred data method, requiring a significantly lower amount of data transfer compared to conventional communications, showed significantly high performance. The coordinates and forces of 101 810 176 atoms and the multipole coefficients of the subcells could be distributed to the 32 768 nodes (1 572 864 cores) in 2.3ms during one MD step calculation. The SIMD effective instruction rates for floating-point arithmetic operations in direct force and fast multipole method (FMM) calculations measured on Fugaku were 78.7% and 31.5%, respectively. The development of a data reuse algorithm enhanced the on-cache processing; the cache miss rate for direct force and FMM calculations was only 2.74% and 1.43%, respectively, on the L1 cache and 0.08% and 0.60%, respectively, on the L2 cache. The modified MODYLAS could complete one MD single time-step calculation within 8.5ms for the aforementioned large system. Additionally, the program contains numerous functions for material research that enable free energy calculations, along with the generation of various ensembles and molecular constraints.

Numerical Evaluation of Wind Speed Influence on Accident Toxic Spill Consequences Scales

This study aims to evaluate numerically the influence of wind speed on scales of environmental harmful consequences caused by accidentally spilled toxic liquid evaporated from the surface of a free-form outlined spill spot. A coupled problem of the gas-dynamic movement of a toxic air-mixture cloud in the surface layer of the atmosphere under the influence of wind and a negative toxic inhalation impact on a human in an accident zone is solved by means of mathematical modelling and computer experiment. Physical processes of toxic liquid evaporation from the spill spot, formation of a mixture of toxic gas with the incoming air, and further dispersion of a hazardous gaseous chemical in the atmosphere under various wind speed conditions are investigated. A three-dimensional non-stationary mathematical model of the turbulent movement of a gas-air mixture is used for obtaining distribution of relative mass concentration of toxic gas impurities in time and space. The model takes into account the complex terrain, compressibility of the gas flow, three-dimensional and non-stationary nature of actual physical processes, different toxic properties of chemical substances, and arbitrary contour shape of the toxic spill spot. A probabilistic harmful impact model based on using a modernized probit analysis method is used to obtain fields of the conditional probability of a fatal human injury resulting from toxic gas inhalation. This model extracts relative mass concentration of toxic gas that could cause negative impact on humans at any control point during calculation time step exposition, collects integral toxic dose values from the multicomponent gas mixture dynamics model, calculates a value of the probit function for the corresponding toxic inhalation dose dangerous factor, and automatically assesses the human fatal injury conditional probability using partial cubic Hermitian spline. This technique allows environmental safety experts assessing the scale of considered type technogenic accident consequences numerically depending on wind speed conditions and elaborating the means to mitigate them to acceptable levels.

CFD-DEM simulation of fluorination reaction in fluidized beds with local grid and time refinement method

The gas-solid reaction process with wide particle size distribution is extensively used in the chemical engineering field, especially the particle reacts with the gas gradually, such as fluorination reactions in fluidized beds. When the computational fluid dynamics-discrete element method (CFD-DEM) is used for the coupling simulation of multiphase and polydisperse particle reaction system, the grid size directly affects the accuracy of flow field information and simulation of chemical reaction. Furthermore, particle calculation time step will directly affect the efficiency of coupling calculation. In this work, a local grid and time step refinement method is proposed to simulate multiphase and polydisperse particle fluidization reaction system. In this method, the refined DEM grids are automatically generated in the computational domain around the fine particles, and the detailed fluid phase information is obtained with the interpolation algorithm. In the two-phase coupling process, particles are divided into different groups based on physical properties, each group has its own independent time step. The multistage conical-cylindrical spouted bed is proposed for the fluorination reaction process; the operating gas velocity range of the polydisperse particle system is extended by the new design while the particle size distribution changes with the gas-solid reaction process. It is demonstrated that the local grid and time step refinement method can improve the accuracy and efficiency of the traditional CFD-DEM method in the reaction process simulation, which describes a polydisperse particle system with wide particle size distribution. Aimed at improving the simulation accuracy and efficiency, this paper will be helpful for simulating the particle reaction process in the gas-solid fluidized bed and beneficial for the development of the CFD-DEM method.

Modelling of Energy-Dependent Electron Interactions in the Earth’s Mesosphere

Electrons are produced in the Earth’s quiet nighttime mesosphere by ionization by cosmic rays and ionization of NO by Lyman-α radiation. They are removed by attachment or recombination processes that are usually assumed in modelling to occur at the ambient temperature. However, the electrons have initial energies that are much higher than at thermal equilibrium, and so must have a range of energies as they progress towards equilibrium via interactions with atoms and molecules. As attachment and recombination rates are dependent on the electron energy, it is possible that modelling that considers the actual energy of the electrons will give different results to those based on assuming that the electrons are at the ambient temperature. In this work, starting with electrons at a higher initial energy, the detailed electron interactions (including elastic scattering and vibrational excitation of molecules) are tracked in a time-step simulation. This simulation is implemented by treating electrons in subranges of the electron energy spectrum as chemical species. This allows an investigation of two phenomena in the nighttime mesosphere: the origin of the D-region ledge and the production of radiative emissions from vibrationally excited molecules. It is found that there is negligible difference in the electron densities calculated using the ambient temperature or detailed interaction models, so this study does not provide an explanation for the D-region ledge. However, in the latter model, emissions at various wavelengths are predicted due to reactions involving vibrationally excited molecules. It is also found, using the time-step calculation, that it would take several hours for the predicted electron density to approach equilibrium.

Modelling Manoeuvrability in the Context of Ship Collision Analysis Using Non-Linear FEM

Ship collisions are rare events that may have a significant impact on the safety of people, ships, and other marine structures, as well as on the environment. Because of this, they are extensively studied but events that just precede collision are often overlooked. To rationally assess collision risks and consequences, a ship’s trajectory, and consequently the velocity and collision angle, should be known. One way to achieve this is through accurate modelling of ship manoeuvrability in collision analysis using non-linear FEM (NFEM). The Abkowitz manoeuvring model is implemented in the LS-Dyna software code and is therefore coupled with FEM calculations. Hydrodynamic forces are calculated in each time step of the LS-Dyna calculation and added to the FE model continuously through calculation. The accuracy of the calculations depends on the choice of and values of hydrodynamic derivatives from the Abkowitz model. Abkowitz’s model derives hydrodynamic forces in the Taylor expansion series to provide hydrodynamic derivatives. The application of the procedure is sensitive on higher-order Taylor series members. This article reviews different sets of hydrodynamic derivatives available for the KVLCC2 ship. Each of them is incorporated into the LS-Dyna NFEM solver by a user-made Fortran subroutine, with standard Zigzag and turning manoeuvres simulated and results compared with the experimental tests. As a result, the optimal selection of hydrodynamic derivatives is determined, laying a foundation for assessing the risk of ship collision due to different ship manoeuvres prior to the collision itself.

Time Steps Distribution in Numerical Technique: A Comparative Analysis of Third and Fourth Order Runge-kutta Algorithms

To analyze a harmonically Van der Pol oscillator, this work used a combination of graphs, time steps distribution, adaptive time steps Runge-Kutta, and fourth order algorithms. The goal is to examine the performance of third and fourth order Runge-Kutta algorithms in finding chaotic solutions for a harmonically excited Van der Pol oscillator. Fourth-order algorithms favor larger time steps and are thus faster to execute than third-order algorithms in all circumstances studied. The accuracy of the data acquired with third order is worth the longer overall computation time steps period reported

Dissipative particle dynamics simulations for biological systems: From protein structures to cell mechanics

<p indent="0mm">Dissipative particle dynamics (DPD) is a mesoscopic coarse-grained simulation method developed in recent years, which is an important method for studying the dynamic behaviors of soft matter and complex fluids. In this method, each DPD particle represents a coarse-grained virtual cluster of a set of atoms or groups of matter. The position and momentum of the DPD particle are updated in a continuous phase but spaced at discrete time steps. The coarse-grained DPD particles are subject to simplified pairwise interacting conservative, dissipative, and random forces. Especially, the dissipative force and random force in the DPD method act as a heat sink and a source, respectively, and the combined effect of these two forces act as a thermostat, which conserves momentum and thus provides the correct description of hydrodynamic interactions for the model system. In addition, a common choice of the soft repulsion for the conservative force allows using larger integration time steps in DPD simulations than that usually allowed in classical molecular dynamics (MD) simulations. Hence, compared with the MD method, the computational cost of the DPD simulation is significantly reduced due to the smaller number of modeled particles and the larger computational time step, enabling the simulations of the static and dynamic behaviors of complex fluids and soft matter systems at physically attractive length scale and time scale. Moreover, the particle-based framework of the DPD method enables people to easily incorporate additional physical features into the model systems and extend its application to complex systems. For these reasons, the DPD method and its extension have been successfully applied to numerous soft matter and complex fluid systems such as oil/water/surfactant systems, chemical morphology, microscopic morphology, phase separation, as well as dynamics and rheological properties of polymer solutions and colloidal suspensions. In this paper, we first introduce the theoretical formulation and parameterization of the DPD method. Then, we review recent advances in DPD modeling of biological systems, focusing on its applications at the molecular and cellular scales. At the molecular scale, we highlight examples of successful simulations of the protein structures and their interactions, the structure and dynamics of amphiphilic lipid molecule membranes (e.g., the self-assembly of lipid molecules, the structure and properties of lipid membranes, the fusion of lipid membranes, and the budding and fission of lipid membranes), the interaction of lipid membranes with protein molecules, and the interaction of nanoparticles with lipid membranes; at the cellular scale, we focus on the DPD modeling of blood cell flow and blood rheological behaviors in the blood microcirculatory systems, including the shape deformation and flow dynamics of red blood cells, the margination and adhesion dynamics of white blood cells, the margination and aggregation behaviors of platelets, the hemorheological behavior of blood flow, as well as the separation of circulating tumor cells from blood flow using microfluidic devices. Additionally, we compare the advantages and disadvantages of the microscale blood flow simulations between the continuum-based methods and particle-based methods, including the DPD method. Finally, we briefly present the development trends and application prospects of DPD modeling in biological systems.