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A large eddy simulation of flows around an underwater vehicle model using an immersed boundary method 被引量:7
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作者 Shizhao Wang Beiji Shi +1 位作者 Yuhang Li Guowei He 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2016年第6期302-305,共4页
A large eddy simulation (LES) of the flows around an underwater vehicle model at intermediate Reynolds numbers is performed. The underwater vehicle model is taken as the DARPA SUBOFF with full appendages, where the ... A large eddy simulation (LES) of the flows around an underwater vehicle model at intermediate Reynolds numbers is performed. The underwater vehicle model is taken as the DARPA SUBOFF with full appendages, where the Reynolds number based on the hull length is 1.0x 105, An immersed boundary method based on the moving-least-squares reconstruction is used to handle the complex geometric boundaries. The adaptive mesh refinement is utilized to resolve the flows near the hull, The parallel scalabilities of the flow solver are tested on meshes with the number of cells varying from 50 million to 3.2 billion, The parallel solver reaches nearly linear scalability for the flows around the underwater vehicle model, The present simulation captures the essential features of the vortex structures near the hull and in the wake, Both of the time-averaged pressure coefficients and srreamwise velocity profiles obtained from the LES are consistent with the characteristics of the flows pass an appended axisymmetric body. The code efficiency and its correct predictions on flow features allow us to perform the full-scale simulations on tens of thousands of cores with billions of grid points for higher-Reynolds-number flows around the underwater vehicles. 展开更多
关键词 Underwater vehicle SUBOFF immersed boundary method Large eddy simulation Adaptive mesh refinement
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Numerical Simulation of Fluid and Heat Transfer in a Biological Tissue Using an Immersed Boundary Method Mimicking the Exact Structure of the Microvascular Network 被引量:7
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作者 Yuanliang Tang Lizhong Mu Ying He 《Fluid Dynamics & Materials Processing》 EI 2020年第2期281-296,共16页
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 cha... 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 fluxes across a capillary wall are distributed to the surrounding tissue nodes by a delta function.We consider both steady and periodic blood pressure conditions at the entrances of the capillary network.Under steady blood pressure conditions,both the interstitial fluid pressure and tissue temperature around the capillary network are larger than those in other places.When the periodic blood pressure condition is considered,tissue temperature tends to fluctuate with the same frequency of the forcing,but the related waveform displays a smaller amplitude and a certain time(phase)delay.When the connectivity of capillary network is diminished,the capacity of blood redistribution through the capillary network becomes weaker and a subset of the vessel branches lose blood flow,which further aggravates the amplitude attenuation and time delay of the skin temperature fluctuation. 展开更多
关键词 Bioheat transfer porous media immersed boundary method DIABETES microvascular dysfunction skin temperature fluctuation
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Numerical Investigation on Vortex-Induced Rotations of A Triangular Cylinder Using An Immersed Boundary Method 被引量:3
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作者 WANG Hua-kun YAN Yu-hao +2 位作者 CHEN Can-ming JI Chun-ning ZHAI Qiu 《China Ocean Engineering》 SCIE EI CSCD 2019年第6期723-733,共11页
A numerical study of vortex-induced rotations(VIRs) of an equivalent triangular cylinder, which is free to rotate in the azimuthal direction in a uniform flow, is presented. Based on an immersed boundary method, the n... A numerical study of vortex-induced rotations(VIRs) of an equivalent triangular cylinder, which is free to rotate in the azimuthal direction in a uniform flow, is presented. Based on an immersed boundary method, the numerical model is established, and is verified through the benchmark problem of flow past a freely rotating rectangular body.The computation is performed for a fixed reduced mass of m~*=2.0 and the structural stiffness and damping ratio are set to zero. The effects of Reynolds number(Re=25-180) on the characteristics of VIR are studied. It is found that the dynamic response of the triangular cylinder exhibits four distinct modes with increasing Re: a rest position,periodic rotational oscillation, random rotation and autorotation. For the rotational oscillation mode, the cylinder undergoes a periodic vibration around an equilibrium position with one side facing the incoming flow. Since the rotation effect, the outset of vortex shedding from cylinder shifts to a much lower Reynolds number. Further increase in Re leads to 2 P and P+S vortex shedding modes besides the typical 2 S pattern. Our simulation results also elucidate that the free rotation significantly changes the drag and lift forces. Inspired by these facts, the effect of free rotation on flow-induced vibration of a triangular cylinder in the in-line and transverse directions is investigated. The results show that when the translational vibration is coupled with rotation, the triangular cylinder presents a galloping response instead of vortex-induced vibration(VIV). 展开更多
关键词 vortex-induced rotation triangular cylinder dynamic response vortex shedding mode immersed boundary method
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Unstructured Grid Immersed Boundary Method for Numerical Simulation of Fluid Structure Interaction 被引量:2
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作者 明平剑 孙扬哲 +1 位作者 段文洋 张文平 《Journal of Marine Science and Application》 2010年第2期181-186,共6页
This paper presents an improved unstructured grid immersed boundary method.The advantages of both immersed boundary method and body fitted grids which are generated by unstructured grid technology are used to enhance ... This paper presents an improved unstructured grid immersed boundary method.The advantages of both immersed boundary method and body fitted grids which are generated by unstructured grid technology are used to enhance the computation efficiency of fluid structure interaction in complex domain.The Navier-Stokes equation was discretized spacially with collocated finite volume method and Euler implicit method in time domain.The rigid body motion was simulated by immersed boundary method in which the fluid and rigid body interface interaction was dealt with VOS(volume of solid) method.A new VOS calculation method based on graph was presented in which both immersed boundary points and cross points were collected in arbitrary order to form a graph.The method is verified with flow past oscillating cylinder. 展开更多
关键词 fluid structure interaction immersed boundary method VOS unstructured grids finite volume method
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Accuracy analysis of immersed boundary method using method of manufactured solutions 被引量:1
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作者 宫兆新 鲁传敬 黄华雄 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2010年第10期1197-1208,共12页
The immersed boundary method is an effective technique for modeling and simulating fluid-structure interactions especially in the area of biomechanics.This paper analyzes the accuracy of the immersed boundary method.T... The immersed boundary method is an effective technique for modeling and simulating fluid-structure interactions especially in the area of biomechanics.This paper analyzes the accuracy of the immersed boundary method.The procedure contains two parts,i.e.,the code verification and the accuracy analysis.The code verification provides the confidence that the code used is free of mistakes,and the accuracy analysis gives the order of accuracy of the immersed boundary method.The method of manufactured solutions is taken as a means for both parts.In the first part,the numerical code employs a second-order discretization scheme,i.e.,it has second-order accuracy in theory.It matches the calculated order of accuracy obtained in the numerical calculation for all variables.This means that the code contains no mistake,which is a premise of the subsequent work.The second part introduces a jump in the manufactured solution for the pressure and adds the corresponding singular forcing terms in the momentum equations.By analyzing the discretization errors,the accuracy of the immersed boundary method is proven to be first order even though the discretization scheme is second order.It has been found that the coarser mesh may not be sensitive enough to capture the influence of the immersed boundary,and the refinement on the Lagrangian markers barely has any effect on the numerical calculation. 展开更多
关键词 manufactured solution immersed boundary method order of accuracy code verification discretization error
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New Immersed Boundary Method on the Adaptive Cartesian Grid Applied to the Local Discontinuous Galerkin Method 被引量:1
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作者 Xu-Jiu Zhang Yong-Sheng Zhu +1 位作者 Ke Yan You-Yun Zhang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2018年第2期176-185,共10页
Currently, many studies on the local discontinuous Galerkin method focus on the Cartesian grid with low computational e ciency and poor adaptability to complex shapes. A new immersed boundary method is presented, and ... Currently, many studies on the local discontinuous Galerkin method focus on the Cartesian grid with low computational e ciency and poor adaptability to complex shapes. A new immersed boundary method is presented, and this method employs the adaptive Cartesian grid to improve the adaptability to complex shapes and the immersed boundary to increase computational e ciency. The new immersed boundary method employs different boundary cells(the physical cell and ghost cell) to impose the boundary condition and the reconstruction algorithm of the ghost cell is the key for this method. The classical model elliptic equation is used to test the method. This method is tested and analyzed from the viewpoints of boundary cell type, error distribution and accuracy. The numerical result shows that the presented method has low error and a good rate of the convergence and works well in complex geometries. The method has good prospect for practical application research of the numerical calculation research. 展开更多
关键词 immersed boundary method Adaptive Cartesian grid Local discontinuous Galerkin method RECONSTRUCTION Heat transfer equation
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Combined immersed boundary method and multiple-relaxation-time lattice Boltzmann flux solver for numerical simulations of incompressible flows 被引量:1
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作者 Xiaodi WU Fu CHEN Huaping LIU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2017年第12期1679-1696,共18页
A method combining the immersed boundary technique and a multi- relaxation-time (MRT) lattice Boltzmann flux solver (LBFS) is presented for numerical simulation of incompressible flows over circular and elliptic c... A method combining the immersed boundary technique and a multi- relaxation-time (MRT) lattice Boltzmann flux solver (LBFS) is presented for numerical simulation of incompressible flows over circular and elliptic cylinders and NACA 0012 Airfoil. The method uses a simple Cartesian mesh to simulate flows past immersed complicated bodies. With the Chapman-Enskog expansion analysis, a transform is performed between the Navier-Stokes and lattice Boltzmann equations (LBEs). The LBFS is used to discretize the macroscopic differential equations with a finite volume method and evaluate the interface fluxes through local reconstruction of the lattice Boltzmann solution. The immersed boundary technique is used to correct the intermediate velocity around the solid boundary to satisfy the no-slip boundary condition. Agreement of simulation results with the data found in the literature shows reliability of the proposed method in simulating laminar flows on a Cartesian mesh. 展开更多
关键词 immersed boundary method lattice Boltzmann equation (LBE) multiple relaxation time incompressible flow
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On the capability of the curvilinear immersed boundary method in predicting near-wall turbulence of turbulent channel flows 被引量:1
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作者 Fei Liao Xiaolei Yang 《Theoretical & Applied Mechanics Letters》 CSCD 2021年第4期213-218,共6页
The immersed boundary method has been widely used for simulating flows over complex geometries.However,its accuracy in predicting the statistics of near-wall turbulence has not been fully tested.In this work,we evalua... The immersed boundary method has been widely used for simulating flows over complex geometries.However,its accuracy in predicting the statistics of near-wall turbulence has not been fully tested.In this work,we evaluate the capability of the curvilinear immersed boundary(CURVIB)method in predicting near-wall velocity and pressure fluctuations in turbulent channel flows.Simulation results show that quantities including the time-averaged streamwise velocity,the rms(root-mean-square)of velocity fluctuations,the rms of vorticity fluctuations,the shear stresses,and the correlation coefficients of u'and v"computed from the CURVIB simulations are in good agreement with those from the body-fitted simulations.More importantly,it is found that the time-averaged pressure,the rms and wavenumber-frequency spectra of pressure fluctuations computed using the CURVIB method agree well with the body-fitted results. 展开更多
关键词 immersed boundary method Turbulent channel flow Wavenumber-frequency spectra Near-wall turbulence
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An extended iterative direct-forcing immersed boundary method in thermo-fluid problems with Dirichlet or Neumann boundary conditions
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作者 Ali Akbar Hosseinjani Ali Ashrafizadeh 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第1期137-154,共18页
An iterative direct-forcing immersed boundary method is extended and used to solve convection heat transfer problems.The pressure,momentum source,and heat source at immersed boundary points are calculated simultaneous... An iterative direct-forcing immersed boundary method is extended and used to solve convection heat transfer problems.The pressure,momentum source,and heat source at immersed boundary points are calculated simultaneously to achieve the best coupling.Solutions of convection heat transfer problems with both Dirichlet and Neumann boundary conditions are presented.Two approaches for the implementation of Neumann boundary condition,i.e.direct and indirect methods,are introduced and compared in terms of accuracy and computational efficiency.Validation test cases include forced convection on a heated cylinder in an unbounded flow field and mixed convection around a circular body in a lid-driven cavity.Furthermore,the proposed method is applied to study the mixed convection around a heated rotating cylinder in a square enclosure with both iso-heat flux and iso-thermal boundary conditions.Computational results show that the order of accuracy of the indirect method is less than the direct method.However,the indirect method takes less computational time both in terms of the implementation of the boundary condition and the post processing time required to compute the heat transfer variables such as the Nusselt number.It is concluded that the iterative direct-forcing immersed boundary method is a powerful technique for the solution of convection heat transfer problems with stationary/moving boundaries and various boundary conditions. 展开更多
关键词 immersed boundary method direct forcing thermo-fluid problems neumann boundary condition
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A three dimensional implicit immersed boundary method with application
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作者 Jian Hao1,2 and Luoding Zhu1, 1)Department of Mathematical Sciences and Center for Mathematical Biosciences Indiana University - Purdue University, Indianapolis, IN 46202, USA 2)Department of Mathematics and Center for Research in Scientific Computation, North Carolina State University, Raleigh, NC 27695, USA 《Theoretical & Applied Mechanics Letters》 CAS 2011年第6期22-25,共4页
Most algorithms of the immersed boundary method originated by Peskin are explicit when it comes to the computation of the elastic forces exerted by the immersed boundary to the fluid. A drawback of such an explicit ap... Most algorithms of the immersed boundary method originated by Peskin are explicit when it comes to the computation of the elastic forces exerted by the immersed boundary to the fluid. A drawback of such an explicit approach is a severe restriction on the time step size for maintaining numerical stability. An implicit immersed boundary method in two dimensions using the lattice Boltzmann approach has been proposed. This paper reports an extension of the method to three dimensions and its application to simulation of a massive flexible sheet interacting with an incompressible viscous flow. 展开更多
关键词 immersed boundary method lattice-Boltzmann method implicit schemes fluid-structure-interaction bi-stability flag-in-wind
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Effect of regularized delta function on accuracy of immersed boundary method
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作者 宫兆新 鲁传敬 黄华雄 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2012年第11期1453-1466,共14页
The immersed boundary method is an effective technique for modeling and simulating fluid-structure interactions especially in the area of biomechanics. The effect of the regularized delta function on the accuracy is a... The immersed boundary method is an effective technique for modeling and simulating fluid-structure interactions especially in the area of biomechanics. The effect of the regularized delta function on the accuracy is an important subject in the property study. A method of manufactured solutions is used in the research. The computational code is first verified to be mistake-free by using smooth manufactured solutions. Then, a jump in the manufactured solution for pressure is introduced to study the accuracy of the immersed boundary method. Four kinds of regularized delta functions are used to test the effect on the accuracy analysis. By analyzing the discretization errors, the accuracy of the immersed boundary method is proved to be first-order. The results show that the regularized delta function cannot improve the accuracy, but it can change the discretization errors in the entire computational domain. 展开更多
关键词 immersed boundary method method of manufactured solutions regularizeddelta function order of accuracy
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A three-dimensional immersed boundary method for non-Newtonian fluids
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作者 Luoding Zhu 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2018年第3期193-196,共4页
Fluid-structure-interaction (FSI) phenomenon is common in science and engineering. The fluidinvolved in an FSI problem may be non-Newtonian such as blood. A popular framework for FSIproblems is Peskin’s imm... Fluid-structure-interaction (FSI) phenomenon is common in science and engineering. The fluidinvolved in an FSI problem may be non-Newtonian such as blood. A popular framework for FSIproblems is Peskin’s immersed boundary (IB) method. However, most of the IB formulations arebased on Newtonian fluids. In this letter, we report an extension of the IB framework to FSIinvolving Oldroyd-B and FENE-P fluids in three dimensions using the lattice Boltzmann approach.The new method is tested on two FSI model problems. Numerical experiments show that themethod is conditionally stable and convergent with the first order of accuracy. 展开更多
关键词 immersed boundary method Lattice Boltzmann method Fluid-structure-interaction Non-Newtonian fluid Oldroyd-BFENE-P
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Heat transfer analysis in particle-laden flows using the immersed boundary method
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作者 Ali Abbas Zaidi 《Particuology》 SCIE EI CAS CSCD 2024年第7期394-403,共10页
This paper investigates an efficient immersed boundary method(IBM)for multiple-core CPU machines with local grid refinement for the calculation of heat transfer between fluids and finite-sized particles.The fluid mome... This paper investigates an efficient immersed boundary method(IBM)for multiple-core CPU machines with local grid refinement for the calculation of heat transfer between fluids and finite-sized particles.The fluid momentum equations are solved by using the fractional step method,while the energy equation is solved by employing the second-order Adams-Bashforth method.For efficient load balancing between the CPU cores,the coupling between particles and fluid is obtained by applying the body force in the fluid equations,which depends on the solid volume fraction of particles contained in each grid cell,and then by linearly interpolating the particle temperature and velocity on the fluid grid cell(in place of the delta function commonly used in literature).Several test cases from the literature are studied,and good agreement is observed between the simulation results and the literature.Finally,a scaling study on multiple core machines is performed,demonstrating the proposed IBM's capabilities for a significant reduction in processing time. 展开更多
关键词 Heat transfer immersed boundary method Particle resolved direct numerical simulations Fluid solid interactions
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A High-Accuracy Curve Boundary Recognition Method Based on the Lattice Boltzmann Method and Immersed Moving Boundary Method
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作者 Jie-Di Weng Yong-Zheng Jiang +2 位作者 Long-Chao Chen Xu Zhang Guan-Yong Zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第9期2533-2557,共25页
Applying numerical simulation technology to investigate fluid-solid interaction involving complex curved bound-aries is vital in aircraft design,ocean,and construction engineering.However,current methods such as Latti... Applying numerical simulation technology to investigate fluid-solid interaction involving complex curved bound-aries is vital in aircraft design,ocean,and construction engineering.However,current methods such as Lattice Boltzmann(LBM)and the immersion boundary method based on solid ratio(IMB)have limitations in identifying custom curved boundaries.Meanwhile,IBM based on velocity correction(IBM-VC)suffers from inaccuracies and numerical instability.Therefore,this study introduces a high-accuracy curve boundary recognition method(IMB-CB),which identifies boundary nodes by moving the search box,and corrects the weighting function in LBM by calculating the solid ratio of the boundary nodes,achieving accurate recognition of custom curve boundaries.In addition,curve boundary image and dot methods are utilized to verify IMB-CB.The findings revealed that IMB-CB can accurately identify the boundary,showing an error of less than 1.8%with 500 lattices.Also,the flow in the custom curve boundary and aerodynamic characteristics of the NACA0012 airfoil are calculated and compared to IBM-VC.Results showed that IMB-CB yields lower lift and drag coefficient errors than IBM-VC,with a 1.45%drag coefficient error.In addition,the characteristic curve of IMB-CB is very stable,whereas that of IBM-VC is not.For the moving boundary problem,LBM-IMB-CB with discrete element method(DEM)is capable of accurately simulating the physical phenomena of multi-moving particle flow in complex curved pipelines.This research proposes a new curve boundary recognition method,which can significantly promote the stability and accuracy of fluid-solid interaction simulations and thus has huge applications in engineering. 展开更多
关键词 Fluid-solid interaction curve boundary recognition method Lattice Boltzmann method immersed moving boundary method
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A Computational Framework for Parachute Inflation Based on Immersed Boundary/Finite Element Approach
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作者 HUANG Yunyao ZHANG Yang +3 位作者 PU Tianmei JIA He WU Shiqing ZHOU Chunhua 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2024年第4期502-514,共13页
A computational framework for parachute inflation is developed based on the immersed boundary/finite element approach within the open-source IBAMR library.The fluid motion is solved by Peskin's diffuse-interface i... A computational framework for parachute inflation is developed based on the immersed boundary/finite element approach within the open-source IBAMR library.The fluid motion is solved by Peskin's diffuse-interface immersed boundary(IB)method,which is attractive for simulating moving-boundary flows with large deformations.The adaptive mesh refinement technique is employed to reduce the computational cost while retain the desired resolution.The dynamic response of the parachute is solved with the finite element approach.The canopy and cables of the parachute system are modeled with the hyperelastic material.A tether force is introduced to impose rigidity constraints for the parachute system.The accuracy and reliability of the present framework is validated by simulating inflation of a constrained square plate.Application of the present framework on several canonical cases further demonstrates its versatility for simulation of parachute inflation. 展开更多
关键词 parachute inflation fluid-structure interaction immersed boundary method finite element method adaptive mesh refinement
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Application of immersed boundary method in turbomachines 被引量:2
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作者 Congcong CHEN Yuwei WANG +2 位作者 Zhuo WANG Lin DU Xiaofeng SUN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2023年第5期268-279,共12页
Simulating unsteady turbulent flow in turbomachines is still challenging due to the complexity of blade geometry and relative motion between rotor and stator.This study presents an Immersed Boundary Method(IBM)for hig... Simulating unsteady turbulent flow in turbomachines is still challenging due to the complexity of blade geometry and relative motion between rotor and stator.This study presents an Immersed Boundary Method(IBM)for high-Reynolds turbomachinery internal flows,and shows the advantage of the automatic grid generation techniques and flexible moving boundary treatments.The wall functions are used in the present method to alleviate the wall resolution restriction of turbulence simulation.The Two-Dimensional(2-D)IBM solver,which was previously developed and tested for a low-speed compressor,is further validated for a well-documented Low-Pressure Turbine(LPT)cascade.Both the blade loading and the total pressure losses in the wake are well captured by the present 2-D solver.The complex Three-Dimensional(3-D)effects in turbomachines motivate the further development of an extended 3-D IBM solver by using a curvilinear-coordinate system that facilitates the hub and casing boundary treatment.The good performance of the 3-D solver is demonstrated through comparison with CFX solver solutions for the rotor configuration of Advanced Noise Control Fan(ANCF).Further effects of the grid resolution on capturing the blade wake are discussed.The results indicate that the present 3-D solver is capable of reproducing the evolution of the blade wake with suitable computational grid. 展开更多
关键词 immersed boundary method TURBOMACHINERY Turbulence simulation Wake prediction Wall function
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Lattice Boltzmann Simulations of Two Linear Microswimmers Using the Immersed Boundary Method
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作者 D.Geyer S.Ziegler +5 位作者 A.Sukhov M.Hubert A.-S.Smith O.Aouane P.Malgaretti J.Harting 《Communications in Computational Physics》 SCIE 2023年第1期310-329,共20页
The performance of a single or the collection of microswimmers strongly depends on the hydrodynamic coupling among their constituents and themselves.We present a numerical study for a single and a pair of microswimmer... The performance of a single or the collection of microswimmers strongly depends on the hydrodynamic coupling among their constituents and themselves.We present a numerical study for a single and a pair of microswimmers based on lattice Boltzmann method(LBM)simulations.Our numerical algorithm consists of two separable parts.Lagrange polynomials provide a discretization of the microswimmers and the lattice Boltzmann method captures the dynamics of the surrounding fluid.The two components couple via an immersed boundary method.We present data for a single swimmer system and our data also show the onset of collective effects and,in particular,an overall velocity increment of clusters of swimmers. 展开更多
关键词 immersed boundary method lattice Boltzmann method finite element method microswimmer collective motion
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Effective Force Stabilising Technique for the Immersed Boundary Method
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作者 Arnab Ghosh Alessandro Gabbana +1 位作者 Herman Wijshoff Federico Toschi 《Communications in Computational Physics》 SCIE 2023年第1期349-366,共18页
The immersed boundary method has emerged as an efficient approach for the simulation of finite-sized solid particles in complex fluid flows.However,one of the well known shortcomings of the method is the limited suppo... The immersed boundary method has emerged as an efficient approach for the simulation of finite-sized solid particles in complex fluid flows.However,one of the well known shortcomings of the method is the limited support for the simulation of light particles,i.e.particles with a density lower than that of the surrounding fluid,both in terms of accuracy and numerical stability.Although a broad literature exists,with several authors reporting different approaches for improving the stability of the method,most of these attempts introduce extra complexities and are very costly from a computational point of view.In this work,we introduce an effective force stabilizing technique,allowing to extend the stability range of the method by filtering spurious oscillations arising when dealing with light-particles,pushing down the particle-to-fluid density ratio as low as 0.04.We thoroughly validate the method comparing with both experimental and numerical data available in literature. 展开更多
关键词 immersed boundary method lattice Boltzmann method light particle force stabilization added mass effect
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NOVEL IMMERSED BOUNDARY-LATTICE BOLTZMANN METHOD BASED ON FEEDBACK LAW 被引量:1
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作者 李秀娟 赵荣国 钟诚文 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2012年第2期179-186,共8页
The lattice Boltzmann method (LBM) and the immersed boundary method (IBM) are alternative, com- putational techniques for solving complex fluid dynamics systems, and can take the place of the Navier-Stokes(N- S)... The lattice Boltzmann method (LBM) and the immersed boundary method (IBM) are alternative, com- putational techniques for solving complex fluid dynamics systems, and can take the place of the Navier-Stokes(N- S) equation. This paper proposes a novel immersed boundary-lattice Boltzmann method (IB-LBM) based on the feedback law. The method uses the immersed boundary concept in the LBM framework to capture the coupling between a body with complex geometry and a uniform fluid, Then, the flows around a stationary circular cylinder and two circular cylinders in a side by side arrangement are simulated by using the method. Results are agreed well with the benchmark data, so, the capability of the method for complex geometry is demonstrated. Different from the conventional IB-LBM, which uses the Hook's law or the direct forcing method to compute the interae- tion force, the method uses the feedback law--the feedback of velocity field and displacement information to calculate the force, thus ensuring the method has advantages of easy implementation and full parallelism. 展开更多
关键词 computational fluid dynamics lattice Boltzmann method immersed boundary method feedback law circular cylinder
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б-sharpen immersed boundary method(б-SIBM)—New method for solving the horizontal pressure-gradient force(PGF) problem of б-coordinate 被引量:1
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作者 HEI PengFei ZHOU Gang +2 位作者 JIA DongDong YE YunTao LEI Kun 《Science China Earth Sciences》 SCIE EI CAS 2014年第7期1681-1691,共11页
Although G-coordinate is one of the most popular methods used in marine and estuarine modeling, it has long suffered from the so-called "steep boundary problem", namely, the PGF problem. In this paper, a new method ... Although G-coordinate is one of the most popular methods used in marine and estuarine modeling, it has long suffered from the so-called "steep boundary problem", namely, the PGF problem. In this paper, a new method called the "σ-sharpen immersed boundary method" (σ-SIBM) is put forward. In this method, the virtual flat bottom boundary is creatively introduced in regions with the steep boundary and is taken as the boundary of numerical domain. By this, OH/Ox of numerical domain changes to be a controllable value and the steep bottom problem is then transformed to the non-conforming boundary problem, which is, in turn, solved by the SIBM. The accuracy and efficiency of the σ-sharpen immersed boundary method (σ-SIBM) has been showed by both comparative theoretical analysis and classical numerical tests. First, it is shown that the σ-SIBM is more effective than the z-level method, in that σ-SIBM needs special treatment only in the steep section, but the z-level method needs the special treatment in each grid note. Second, it is superior to the p-method in that it is not restricted by the density distribution. This paper revisits the classical seamount numerical test used in numerous studies to prove the sigma errors of the pressure gradient force (PGFE) and their long-term effects on circulation. It can be seen that, as for the maximum erroneous velocity and kinetic energy, the value of σ-SIBM is much less than that of the z-level method and the traditional σ-method. 展开更多
关键词 sharpen immersed boundary method (SIBM) immersed boundary method (IBM) direct forcing method o-coordinate pressure gradient force (PGF)
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