Home / Advanced Search

  • Title/Keywords

  • Author/Affliations

  • Journal

  • Article Type

  • Start Year

  • End Year

Update SearchingClear
  • Articles
  • Online
Search Results (14)
  • Open Access


    A Hybrid Immersed Boundary/Coarse-Graining Method for Modeling Inextensible Semi-Flexible Filaments in Thermally Fluctuating Fluids

    Magdalini Ntetsika, Panayiotis Papadopoulos*

    CMES-Computer Modeling in Engineering & Sciences, Vol.129, No.3, pp. 1243-1258, 2021, DOI:10.32604/cmes.2021.017404

    Abstract A new and computationally efficient version of the immersed boundary method, which is combined with the coarse-graining method, is introduced for modeling inextensible filaments immersed in low-Reynolds number flows. This is used to represent actin biopolymers, which are constituent elements of the cytoskeleton, a complex network-like structure that plays a fundamental role in shape morphology. An extension of the traditional immersed boundary method to include a stochastic stress tensor is also proposed in order to model the thermal fluctuations in the fluid at smaller scales. By way of validation, the response of a single, massless, inextensible semiflexible filament immersed in… More >

  • Open Access


    Numerical Simulation of Fluid and Heat Transfer in a Biological Tissue Using an Immersed Boundary Method Mimicking the Exact Structure of the Microvascular Network

    Yuanliang Tang1, 2, Lizhong Mu1, Ying He1, *

    FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.2, pp. 281-296, 2020, DOI:10.32604/fdmp.2020.06760

    Abstract The aim of this study is to develop a model of fluid and heat transfer in a biological tissue taking into account the exact structure of the related microvascular network, and to analyze the influence of structural changes of such a network induced by diabetes. A cubic region representing local skin tissue is selected as the computational domain, which in turn includes two intravascular and extravascular sub-domains. To save computational resources, the capillary network is reduced to a 1D pipeline model and embedded into the extravascular region. On the basis of the immersed boundary method (IBM) strategy, fluid and heat… More >

  • Open Access


    Numerical Analysis of Motion and Stress Distribution of Circulating Tumor Cells in Micro Vessels

    Peng Jing1, Xiaolong Wang1, Shigeho Noda2, Xiaobo Gong1,*

    Molecular & Cellular Biomechanics, Vol.16, Suppl.2, pp. 36-37, 2019, DOI:10.32604/mcb.2019.07111

    Abstract The motion of circulating tumor cells (CTCs) in microcirculatory system is one of the critical steps during cancer metastasis. The moving behavior and stress distribution of circulating tumor cells under different geometry and flow conditions are important basis for studying the adhesion between circulating tumor cells and vessel walls. In the present work, the motion and deformation of circulating tumor cells in capillary tubes are numerically studied using the immersed boundary method (IBM). The membrane stress distribution of CTCs in confined tubes are investigated with under vessel diameters, hematocrit (Ht) values and capillary numbers (Ca). The results show that the… More >

  • Open Access


    A Numerical Study of the Influence of Surface Roughness on the Convective Heat Transfer in a Gas Flow

    F. Dierich1, P.A. Nikrityuk1

    CMES-Computer Modeling in Engineering & Sciences, Vol.64, No.3, pp. 251-266, 2010, DOI:10.3970/cmes.2010.064.251

    Abstract This work presents a numerical investigation of the influence of the roughness of a cylindrical particle on the drag coefficient and the Nusselt number at low Reynolds numbers up to 40. The heated cylindrical particle is placed horizontally in a uniform flow. Immersed boundary method (IBM) with a continuous forcing on a fixed Cartesian grid is used. The governing equations are the Navier Stokes equation and the conservation of energy. A finite-volume based discretization and the SIMPLE algorithm with collocated-variables and Rie-Chow stabilization were used to solve the set of equations. Numerical simulations showed that the impact of the roughness… More >

  • Open Access


    An IB Method for Non-Newtonian-Fluid Flexible-Structure Interactions in Three-Dimensions

    Luoding Zhu1,∗

    CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.1, pp. 125-143, 2019, DOI:10.32604/cmes.2019.04828

    Abstract Problems involving fluid flexible-structure interactions (FFSI) are ubiquitous in engineering and sciences. Peskin’s immersed boundary (IB) method is the first framework for modeling and simulation of such problems. This paper addresses a three-dimensional extension of the IB framework for non-Newtonian fluids which include power-law fluid, Oldroyd-B fluid, and FENE-P fluid. The motion of the non-Newtonian fluids are modelled by the lattice Boltzmann equations (D3Q19 model). The differential constitutive equations of Oldroyd-B and FENE-P fluids are solved by the D3Q7 model. Numerical results indicate that the new method is first-order accurate and conditionally stable. To show the capability of the new… More >

  • Open Access


    An Immersed Method Based on Cut-Cells for the Simulation of 2D Incompressible Fluid Flows Past Solid Structures

    François Bouchon1, *, Thierry Dubois1, Nicolas James2

    CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.1, pp. 165-184, 2019, DOI:10.32604/cmes.2019.04841

    Abstract We present a cut-cell method for the simulation of 2D incompressible flows past obstacles. It consists in using the MAC scheme on cartesian grids and imposing Dirchlet boundary conditions for the velocity field on the boundary of solid structures following the Shortley-Weller formulation. In order to ensure local conservation properties, viscous and convecting terms are discretized in a finite volume way. The scheme is second order implicit in time for the linear part, the linear systems are solved by the use of the capacitance matrix method for non-moving obstacles. Numerical results of flows around an impulsively started circular cylinder are… More >

  • Open Access


    An Augmented IB Method & Analysis for Elliptic BVP on Irregular Domains

    Zhilin Li1,∗, Baiying Dong2, Fenghua Tong3, Weilong Wang3

    CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.1, pp. 63-72, 2019, DOI:10.32604/cmes.2019.04635

    Abstract The immersed boundary method is well-known, popular, and has had vast areas of applications due to its simplicity and robustness even though it is only first order accurate near the interface. In this paper, an immersed boundary-augmented method has been developed for linear elliptic boundary value problems on arbitrary domains (exterior or interior) with a Dirichlet boundary condition. The new method inherits the simplicity, robustness, and first order convergence of the IB method but also provides asymptotic first order convergence of partial derivatives. Numerical examples are provided to confirm the analysis. More >

  • Open Access


    Variable Viscosity and Density Biofilm Simulations using an Immersed Boundary Method, Part I: Numerical Scheme and Convergence Results

    Jason F. Hammond1, Elizabeth J. Stewart2, John G. Younger3, Michael J.Solomon2, David M. Bortz4,5

    CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.3, pp. 295-340, 2014, DOI:10.32604/cmes.2014.098.295

    Abstract The overall goal of this work is to develop a numerical simulation which correctly describes a bacterial biofilm fluid-structure interaction and separation process. In this, the first of a two-part effort, we fully develop a convergent scheme and provide numerical evidence for the method order as well as a full 3D separation simulation. We use an immersed boundary-based method (IBM) to model and simulate a biofilm with density and viscosity values different from than that of the surrounding fluid. The simulation also includes breakable springs connecting the bacteria in the biofilm which allows the inclusion of erosion and detachment into… More >

  • Open Access


    A Direct Forcing Immersed Boundary Method Employed With Compact Integrated RBF Approximations For Heat Transfer and Fluid Flow Problems

    N. Thai-Quang1, N. Mai-Duy1, C.-D. Tran1, T. Tran-Cong1,2

    CMES-Computer Modeling in Engineering & Sciences, Vol.96, No.1, pp. 49-90, 2013, DOI:10.3970/cmes.2013.096.049

    Abstract In this paper, we present a numerical scheme, based on the direct forcing immersed boundary (DFIB) approach and compact integrated radial basis function (CIRBF) approximations, for solving the Navier-Stokes equations in two dimensions. The problem domain of complicated shape is embedded in a Cartesian grid containing Eulerian nodes. Non-slip conditions on the inner boundaries, represented by Lagrangian nodes, are imposed by means of the DFIB method, in which a smoothed version of the discrete delta functions is utilised to transfer the physical quantities between two types of nodes. The velocities and pressure variables are approximated locally on Eulerian nodes using… More >

  • Open Access


    Simulation of Three-dimensional Complex Flows in Injection Molding Using Immersed Boundary Method

    Qiang Li1

    CMES-Computer Modeling in Engineering & Sciences, Vol.94, No.3, pp. 207-224, 2013, DOI:10.32604/cmes.2013.094.207

    Abstract In this paper, an immersed boundary method (IBM) has been developed to simulate three-dimensional (3D) complex flows in the injection molding process, in which the irregular boundary of mould is treated by a level set function. The melt front (melt-air interface) is captured and treated using the coupled level set and volume of fluid (CLSVOF) method. The finite volume method on the nonstaggered meshes is implemented to solve the governing equations, and the melt filling process is simulated in a rectangular mould with both thick- and thin-wall sections. The numerical result shows good agreement with the available data. Finally, the… More >

Displaying 1-10 on page 1 of 14. Per Page  

Share Link