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Fixed-interval smoothing of an aeroelastic airfoil model with cubic or free-play nonlinearity in incompressible flow

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Acta Mechanica Sinica 2021年第7期37卷 1168-1182,I0003页

作者： Qi Liu Yong Xu Yongge Li Jurgen Kurths Xiaochuan Liu School of Mathematics and Statistics Northwestern Polytechnical UniversityXi’an 710072China MIIT Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical UniversityXi’an 710072China Potsdam Institute for Climate Impact Research Potsdam 14473Germany Lobachevsky University of Nizhny Novgorod Nizhnij NovgorodRussia AVIC Aircraft Strength Research Institute Xi’an 710065China

Fixed-interval smoothing,as one of the most important types of state estimation,has been concerned in many practical problems especially in the analysis of flight test ***,the existing sequential filters and smoothers usually cannot deal with nonlinear or high-dimensional systems well.A state-of-the-art technique is employed in this study to explore the fixed-interval smoothing problem of a conceptual two-dimensional airfoil model in incompressible flow from noisy measurement ***,the governing equations of the airfoil model are assumed to be known or only partially known.A single objective optimization problem is constructed with the classical Runge–Kutta scheme,and then estimations of the system states,the measurement noise and even the unknown parameters are obtained simultaneously through minimizing the objective *** and feasibility of the method are examined under several simulated measurement data corrupted by different measurement *** the obtained results indicate that the introduced algorithm is applicable for the airfoil model with cubic or free-play structural nonlinearity and leads to accurate state and parameter ***,it is highly robust to Gaussian white and even more complex heavy-tailed measurement *** should be emphasized that the employed algorithm is still effective to high-dimensional nonlinear aeroelastic systems.

关键词： Airfoil model incompressible flow State estimation Parameter estimation

A MATRIX-FREE IMPLICIT METHOD FOR incompressible flow AROUND 3D COMPLEX UNDERWATER BODIES

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Journal of Hydrodynamics 2006年第2期18卷 192-198页

作者： HUANG Zhen-yu Miao Guo-ping School of Naval Architecture Ocean and Civil Engineering Shanghai Jiaotong University Shanghai 200030China China Ship Scientific Research Center Wuxi 214082 China

A fast, matrix-free implicit method based on the Lower-Upper Symmetric Gauss-Seidel （LU-SGS） method was developed to solve the three-dimensional incompressible Reynolds-averaged Navier-Stokes equations on multi-block structured grids. The method was applied to the simulations of a variety of flowfields around 3D complex underwater bodies with different appendages. The numerical procedure and results show that the method is efficient, reliable and robust for steady viscous flow simulations.

关键词： Lower-Upper Symmetric Gauss-Seidel(LU-SGS) method incompressible flow underwater bodies,Computational Fluid Dynamics (CFD)

USE THE EQUATIONS OF TOTAL PRESSURE AND VELOCITY TO SOLVE THE VISCOUS incompressible flow IN THE CHANNEL

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Journal of Hydrodynamics 1993年第1期5卷 63-69页

作者： Jiang, Jinliang Shanghai Inst of Electric Power Shanghai China

This paper presents a new method to numerically solve the viscous incompress- ible steady flow in a channel with non-uniform section by use of the equations of total pressure and *** method is to solve the equations o... 详细信息

关键词： viscous flow incompressible flow channel with non-uniform section

Combined adaptive meshing technique and characteristic-based split algorithm for viscous incompressible flow analysis

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Applied Mathematics and Mechanics(English Edition) 2007年第9期28卷 1163-1172页

作者： Suthee Traivivatana Parinya Boonmarlert Patcharee Theeraek Sutthisak Phongthanapanich Pramote Dechaumphai Department of Mechanical Engineering Faculty of EngineeringChulalongkorn UniversityPatumwanBangkok 10330Thailand Department of Mechanical Engineering Technology College of Industrial TechnologyKing Mongkut's Institute of Technology North BangkokBangsueBangkok 10800Thailand

A combined characteristic-based split algorithm and all adaptive meshing technique for analyzing two-dimensional viscous incompressible flow are presented. Tile method uses the three-node triangular element with equal-order interpolation functions for all variables of tile velocity components and pressure. The main advantage of the combined nlethod is that it inlproves the sohltion accuracy by coupling an error estinla- tion procedure to an adaptive meshing technique that generates small elements in regions with a large change ill sohmtion gradients, mid at the same time, larger elements in the other regions. The performance of the combined procedure is evaluated by analyzing one test case of the flow past a cylinder, for their transient and steady-state flow behaviors.

关键词： adaptive mesh characteristic-based split finite element method incompressible flow

A Staggered Grid Method for Solving incompressible flow on Unstructured Meshes

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Computer Modeling in Engineering & Sciences 2020年第5期123卷 509-523页

作者： Huawen Shu Minghai Xu Xinyue Duan Yongtong Li Yu Sun Ruitian Li Peng Ding College of New Energy China University of Petroleum(East China)Qingdao266580China

A finite volume method based unstructured grid is presented to solve the two dimensional viscous and incompressible *** method is based on the pressure-correction concept and solved by using a semi-staggered grid *** computational procedure can handle cells of arbitrary shapes,although solutions presented in this paper were only involved with triangular and quadrilateral *** pressure or pressure-correction value was stored on the vertex of *** mass conservation equation was discretized on the dual cells surrounding the vertex of primary cells,while the velocity components and other scale variables were saved on the central of primary *** the semi-staggered arrangement can’t guarantee a strong coupling relationship between pressure and velocity,thus a weak coupling relationship leads to the oscillations for pressure and *** order to eliminate such an oscillation,a special interpolation scheme was used to construct the pressure-correction *** results of several viscous flow problems show good agreement with the analytical or numerical results in previous *** semi-staggered grid method can be applied to arbitrary shape elements,while it has the most efficiency for triangular cells.

关键词： Staggered grid incompressible flow pressure correction finite volume method

A class of nonconforming quadrilateral finite elements for incompressible flow

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Science China Mathematics 2013年第2期56卷 379-393页

作者： HUANG ZhongYi LI Ye Department of Mathematical Sciences Tsinghua University

This paper focuses on the low-order nonconforming rectangular and quadrilateral finite elements approximation of incompressible *** the previous research works,we propose a general strategy to construct the basis *** several specific constraints,the optimal error estimates are obtained,i.e.,the first order accuracy of the velocities in H1-norm and the pressure in L2-norm,as well as the second order accuracy of the velocities in ***,we clarify the differences between rectangular and quadrilateral finite element *** addition,we give several examples to verify the validity of our error estimates.

关键词： incompressible flow finite element method nonconforming quadrilateral elements optimal error estimates

Two-Scale Picard Stabilized Finite Volume Method for the incompressible flow

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Advances in Applied Mathematics and Mechanics 2014年第5期6卷 663-679页

作者： Jianhong Yang Gang Lei Jianwei Yang Department of Mathematics Baoji University of Arts and SciencesBaoji 721013China Department of Computer and Science Baoji University of Arts and SciencesBaoji 721007China

In this paper,we consider a two-scale stabilized finite volume method for the two-dimensional stationary incompressible flow approximated by the lowest equalorder element pair P_(1)−P_(1)which do not satisfy the inf-sup *** two-scale method consist of solving a small non-linear system on the coarse mesh and then solving a linear Stokes equations on the fine *** of the optimal order in the H1-norm for velocity and the L^(2)-norm for pressure are *** error analysis shows there is the same convergence rate between the two-scale stabilized finite volume solution and the usual stabilized finite volume solution on a fine mesh with relation h=O(H^(2)).Numerical experiments completely confirm theoretic ***,this method presented in this paper is of practical importance in scientific computation.

关键词： incompressible flow stabilized finite volume method inf-sup condition local Gauss integral two-scale method

A Jacobian-Free Newton Krylov Implicit-Explicit Time Integration Method for incompressible flow Problems

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Communications in Computational Physics 2013年第5期13卷 1408-1431页

作者： Samet Y.Kadioglu Dana A.Knoll Department of Mathematical Engineering Yildiz Technical University34210 Davutpasa-EsenlerIstanbulTurkey Fuels Modeling and Simulation Department Idaho National LaboratoryP.O.Box 1625MS 3840Idaho FallsID 83415USA Theoretical Division Los Alamos National LaboratoryP.O.Box 1663MS B-216Los AlamosNM87545USA

We have introduced a fully second order IMplicit/EXplicit(IMEX)time integration technique for solving the compressible Euler equations plus nonlinear heat conduction problems(also known as the radiation hydrodynamics problems)in Kadioglu et al.,***[22,24].In this paper,we study the implications when this method is applied to the incompressible Navier-Stokes(N-S)*** IMEX method is applied to the incompressible flow equations in the following *** hyperbolic terms of the flow equations are solved explicitly exploiting the well understood explicit *** the other hand,an implicit strategy is employed for the non-hyperbolic *** explicit part is embedded in the implicit step in such a way that it is solved as part of the non-linear function evaluation within the framework of the Jacobian-Free Newton Krylov(JFNK)method[8,29,31].This is done to obtain a self-consistent implementation of the IMEX method that eliminates the potential order reduction in time accuracy due to the specific operator *** employ a simple yet quite effective fractional step projection methodology(similar to those in[11,19,21,30])as our preconditioner inside the JFNK *** present results from several test *** each test,we show second order time ***,we present a study for the algorithm performance of the JFNK solver with the new projection method based preconditioner.

关键词： incompressible flow Navier-Stokes equations IMEX method JFNK method preconditioner

Numerical Simulation of an Aortic flow Based on a HLLC Type incompressible flow Solver

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Communications in Computational Physics 2009年第1期5卷 142-162页

作者： Yang-Yao Niu Chih-Hung Chang Wen-Yih I.Tseng Hsu-Hsia Peng Hsi-Yu Yu Department of Mechanical Engineering Chung-Hua UniversityHsin-Chu30067 Taiwan National Taiwan University Hospital No.7Chung-Shan South RoadTaipeiTaiwan

In this study,a three-dimensional artificial compressibility solver based on the average-state Harten-Lax-van Leer-Contact(HLLC)[13]type Riemann solution is first proposed and developed to solve the time-dependent incompressible flow *** implement unsteady flow calculations,a dual time stepping strategy including the LU decomposition method is used in the pseudo-time iteration and the second-order accurate backward difference is adopted to discretize the unsteady flow *** a third-order accurate HLLC numerical flux is derived for approximating the inviscid *** verify numerical accuracy,flows over a lid-driven cavity and an oscillating flat plate are chosen as the benchmark *** addition,the current solver is extended to solve blood flows in a realistic human aorta measured from MRI(Magnetic Resonance Imaging).The simulation geometry was derived from a three-dimensional reconstruction of a series of two-dimensional slices obtained in *** results demonstrate wall stresses were highly dynamic,but were generally high along the outer wall in the vicinity of the branches and low along the inner wall,particularly in the descending *** maximum wall stress distribution is presented on the aortic arch in the *** addition,extensive counter-clockwise secondary flows and three-dimensional helical vortex influenced considerably by the presence of vessel contraction,torsion and the branches were shown in the descending aorta in the late systole and early diastolic cycles.

关键词： HLLC Riemann solver incompressible flow aortic flow fluid-structure interaction