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Transient growth in Poiseuille-Rayleigh-Bénard flows of binary fluids with Soret effect

Applied Mathematics and Mechanics(English Edition) 2016年第9期37卷 1203-1218页

作者： Jun HU D.HENRY H.BENHADID xieyuan yin Institute of Applied Physics and Computational Mathematics Beijing 100088China Laboratoire de Mecanique des Fluides et d'Acoustique CNRS/Universitd de LyonEcole Centrale de Lyon/universite Lyon 1/INSA de LyonECL36 avenue Guy de Collongue69134 Ecully CedexFrance Department of Modern Mechanics University of Science and Technology of ChinaHefei 230027China

The transient growth due to non-normMity is investigated for the Poiseuille- Rayleigh-Benard problem of binary fluids with the Soret effect. For negative separation factors such as ψ = -0.1, it is found that a large transient growth can be obtained by the non-normal interaction of the two least-stable-modes, i.e., the upstream and downstream modes, which determine the linear critical boundary curves for small Reynolds numbers. The transient growth is so strong that the optimal energy amplification factor G（t） is up to 10^2 - 10^3. While for positive separation factors such as ψ = 0.1, the transient growth is weak with the order O（I） of the amplification factor, which can even be computed by the least-stable-mode. However, for both cases, the least-stable-mode can govern the long-term behavior of the amplification factor for large time. The results also show that large Reynolds numbers have stabilization effects for the maximum amplification within moderate wave number regions. Meanwhile, much small negative or large positive separation factors and large Rayleigh numbers can enlarge the maximum transient growth of the pure streamwise disturbance with the wavenumber α= 3.14. Moreover, the initial and evolutionary two-dimensional spatial patterns of the large transient growth for the pure streamwise disturbance are exhibited with a plot of the velocity vector, spanwise vorticity, temperature, and concentration field. The initial three-layer cell vorticity struc- ture is revealed. When the amplification factor reaches the maximum Gmax, it develops into one cell structure with large amplification for the vorticity strength.

关键词： binary fluid Soret effect transient growth Poiseuille-Rayleigh-Benard flow

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STUDY ON FORCED SHEAR FLOW BY A OSCILLATING SPOILER

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Acta Mechanica Sinica 1989年第3期5卷 205-215页

作者： yin xieyuan Ouyang Liangbiao (Univ.of Sci.& Tech.of China) 1. Univ. of Sci. & Tech. of China China

In the present paper,numerical solution of the two-dimensional unsteady Navier-Stokes equations is used to study the forced shear flow induced by a spoiler's periodical up and down oscillation on a flat *** paper studies the evolution of growing,shedding,merging and decaying of vortices due to the spoiler's oscillation,particularly the dependence of the forced shear flow on the re- duced *** show that the reduced frequency is a key factor in controlling the growing and the shedding of vortices in the shear *** instantaneous streamlines and the equi-vorticity con- tours,as well as the surface pressure distributions,have also been *** results agree well with corresponding experimental *** study is helpful for understanding the physical mecha- nism of shear flow control.

关键词： shear flow unsteady separated flow spoiler

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Numerical simulation of two-dimensional interface breakup

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Progress in Natural Science:Materials International 2006年第5期16卷 554-558页

作者： CAI Yong,MA Dongjun, SUN Dejun and yin xieyuan (Department of Modern Mechanics, University of Science and Technology of China, Hefei 230027, China) [a]Department of Modern Mechanics University of Science and Technology of China Hefie China

The nonlinear evolution of the two-dimensional mixing layer flow of two immiscible fluids separated by the interface with surface tension is simulated numerically. The volume of the fluid method is used to capture the motion of the interface. A parametric study is conducted to investigate the effects of Weber number, Reynolds number, and the density ratio, etc. on the breaking process.

关键词： interface surface tension volume of fluid

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A source term model of perturbation in a numerical study on flows around a slender body of revolution at a high angle of attack

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Progress in Natural Science:Materials International 2009年第12期19卷 1831-1835页

作者： Yang Liu,Dongjun Ma,Dejun Sun~*,xieyuan yin Department of Modern Mechanics,University of Science and Technology of China,Hefei 230027,China [a]Department of Modern Mechanics University of Science and Technology of China Hefei 230027 China

A numerical study on flows around a slender body of revolution at a high angle of attack is conducted to investigate the influence of strength and circumferential angle of perturbation on flow asymmetry.A source term model is applied to simulate a real geometrical perturbation near the tip of the slender *** can greatly facilitate the adjustment of perturbation *** results show that the bistable phenomenon does not appear any more at a small perturbation *** different perturbation strengths,the energy of the asymmetric perturbation flow experiences a similar spatial exponential growth regime with the same growth *** appearance of the bistable phenomenon is closely related to nonlinear saturation of the perturbation flow as perturbation strength increases.

关键词： Slender body High angle of attack Asymmetric vortex Source term model

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NUMERICAL SIMULATION OF UNSTEADY FLOW AROUND A CIRCULAR CYLINDER AT HIGH REYNOLDS NUMBERS

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Chinese Journal of Aeronautics 1991年第2期6卷 198-206页

作者： yin xieyuan Tong Bingang University of Science and Technology of ChinaHefei, Anhui, 230026, ChinaTao Feng Institute of Mechanics, Acadmia Sinica,Beijing, 100080, China

A Lagrangian-Eulerian hybrid scheme to solve unsteady N-S equation in two-dimensional incompressible fluid at high Reynolds numbers is presented in this paper. A random walk is imposed to simulate the viscous diffusion, the vortex-in-cell method is used to obtain the convection velocity, and nascent vortices are created on a cylinder to satisfy the zero-slip condition. The impulsively started flow around a circular cylinder and the separation induced by a pair of incident vortices symmetrically approaching a circular cylinder have been successfully simulated by the hybrid scheme. The impulsively started flow from rest has been computed at Reynolds numbers 3000 and 9500. Comparisons are made with those results of finite-difference method, vortex method and flow visualization. Agreement is good. The particular attention has been paid to the evolutions of flow pattern. A topological analysis has been proposed in the region of the near wake. The bulge, isolated secondary vortex, a pair of secondary vortices, ' forewake phenomenon and other patterns are simulated numerically. The separation induced by a pair of incident vortices approaching a circular cylinder has been investigated by using the same scheme. The rebounding phenomenon of the incident vortex is observed and is attributed to the effect of the secondary vortex. In particular, we have found that a tertiary vortex can be formed near the surface; this phenomenon has been verified by flow visualization reported recently.

关键词： NUMERICAL SIMULATION OF UNSTEADY FLOW AROUND A CIRCULAR CYLINDER AT HIGH REYNOLDS NUMBERS AT

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高阶谱元区域分解算法及其在流动稳定性中的应用

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计算物理 2007年第1期24卷 7-12页

作者：马东军孙德军尹协远中国科学技术大学工程科学学院安徽合肥230027

以无时间分裂误差的区域分解Stokes谱元算法为基础构建整体稳定性分析方法.用Jacobian-free的Inexact-Newton-Krylov算法求解不可压缩Navier-Stokes方程的定常解,将Stokes算法的时间推进步作为Newton迭代的预处理,在此基础上采用Arnold... 详细信息

以无时间分裂误差的区域分解Stokes谱元算法为基础构建整体稳定性分析方法.用Jacobian-free的Inexact-Newton-Krylov算法求解不可压缩Navier-Stokes方程的定常解,将Stokes算法的时间推进步作为Newton迭代的预处理,在此基础上采用Arnoldi方法计算大规模特征值问题,对复杂流动进行稳定性分析,该方法能统一处理定常和非定常计算,没有时间分裂误差,无需显式构造Jacobian矩阵,可以减少内存使用,降低计算量,并加速迭代收敛.对有分析解的Kovasznay流动的计算表明,高阶谱元法具有指数收敛的谱精度.对亚临界方腔对称驱动流的各种定常解的计算及其稳定性分析验证了方法的可行性.

关键词：高阶谱元法非精确Newton—Krylov方法 Amoldi方法流动稳定性

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LOW-DIMENSIONAL GALERKIN METHOD AND ITS ROLE IN QUALITATIVE ANALYSIS OF NONLINEAR BEHAVIOR OF BLUFF BODY WAKES

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中国科学院大学学报 1998年第2期 2-9页

作者： Tong Binggang (The Graduate School at Beijing,University of Science and Technology of China,Beijing 100039) yin xieyuan\ \ Sun Dejun\ \ Hu Guohui (Department of Modern Mechanics,University of Science and Technology of China,Hefei 230026)\ \

１ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆＣＦＤａｉｍｅｄｎｏｔｏｎｌｙａｔｔｈｅｃａｐａｂｉｌｉｔｙｏｆｃｏｍｐｌｅｘｆｌｏｗｃｏｍｐｕｔａｔｉｏｎｓｗｉｔｈｈｉｇｈａｃｃｕｒａｃｙａｎｄｈｉｇｈｅ... 详细信息

１ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆＣＦＤａｉｍｅｄｎｏｔｏｎｌｙａｔｔｈｅｃａｐａｂｉｌｉｔｙｏｆｃｏｍｐｌｅｘｆｌｏｗｃｏｍｐｕｔａｔｉｏｎｓｗｉｔｈｈｉｇｈａｃｃｕｒａｃｙａｎｄｈｉｇｈｅｆｉｃｉｅｎｃｙ，ｂｕｔａｌｓｏａ...

关键词： low dimensional Galerkin method cylinder wake flow instability and bifurcation study Karman vortex street Floquet stability analysis

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振荡扰流片非定常流场的N-S方程数值模拟

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航空学报 1989年第11期10卷 A529-A535页

作者：欧阳良彪尹协远中国科技大学

通过有限差分法求解不可压缩流体的二维非定常Navier-Stokes方程,研究扰流片作振荡运动引起的强迫非定常分离流特性。着重研究了雷诺数、缩减频率等因素的影响。得到涡在扰流片上生成、发展、脱落以及脱落后的演化过程;并给出扰流片和... 详细信息

通过有限差分法求解不可压缩流体的二维非定常Navier-Stokes方程,研究扰流片作振荡运动引起的强迫非定常分离流特性。着重研究了雷诺数、缩减频率等因素的影响。得到涡在扰流片上生成、发展、脱落以及脱落后的演化过程;并给出扰流片和平板表面的压力分布。计算结果和实验结果符合良好。

关键词：非定常流 N-S方程扰流片分离流

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Van der Waals状态方程可压缩多流体流动的PPM方法

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计算物理 2007年第3期24卷 287-294页

作者：郑建国马东军孙德军尹协远中国科学技术大学工程科学学院安徽合肥230027

基于流体体积分数的混合型多流体数值模型,将Piecewise Parabolic Method(PPM)方法应用于可压缩多流体流动的数值模拟,采用双波近似求解多流体van der Waals状态方程的Riemann问题.模拟高密度比且含有激波的可压缩多流体流动,典型的纯... 详细信息

基于流体体积分数的混合型多流体数值模型,将Piecewise Parabolic Method(PPM)方法应用于可压缩多流体流动的数值模拟,采用双波近似求解多流体van der Waals状态方程的Riemann问题.模拟高密度比且含有激波的可压缩多流体流动,典型的纯界面平移问题模拟结果表明,在接触间断的界面附近,压力和速度没有任何的振荡且界面数值耗散都被控制在2-3个网格之内;一维和二维算例表明,该数值方法可以有效地处理接触间断、激波和多维滑移线等物理问题,并能够比其它多流体数值方法更精细地模拟多流体交界面.

关键词：混合型多流体模型 van der waals状态方程高阶G0dunov格式 Riemann问题

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细长机翼非线性升力和压心的近似解析计算法

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航空学报 1980年第1期 1-6页

作者：尹协远中国科技大学

本文给出了计算前、侧缘涡升力及其压心的一种近似简化分析方法,同时给出两个经验修正公式,与其它方法和实验数据比较表明,本方法精度良好,可以满足工程设计的需要。

关键词：涡升力翼面侧缘前缘涡梯形翼压心

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