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本文分析了一种非定常振荡的不稳定性问题。其特点是,应用偏微分方程特征理论以及O-S方程特征值的展开,求解扰动波的相函数而不是预先给定扰动波的波动形式。本文研究平面Poisettille流与其垂向振荡流的组合流动系统,对于连续振荡源导致的波包演化,该系统存在不稳定性。 相似文献
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An investigation is described for instability problem of flow through a pipe of circularcross-section.As a disturbance motion,we consider a general non-axisymmetric mode.Anassociated amplitude or modulation equation has been derived for this disturbance motion.This equation belongs to a diffusion type.The coefficient of it can be negative whileReynolds number increases,because of the complex interaction between moleculardiffusion and convection.The negative diffusivity,when it occurs,causes a concentrationand focussing of energy within decaying slugs,acting as a role of reversing natural decays 相似文献
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本文主要讨论高雷诺数下平面Poiseuille流稳定性问题.应用多层结构分析理论,求出了描述该流体稳定性的Orr-Sommerfeld方程特征值的较为合理的逼近式及相应的特征函数的渐近解析解. 相似文献
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本文讨论用有限元求解Orr-Sommerfeld方程的方法。由于选取7阶Hermite多项式为元素的基函数和按照流体在各个区域中的不同物理特性选取元素的网格分布,保证了函数在元素节点处C3连续及计算误差的较好控制,所得的结果比以前较为准确。应用这种方法讨论Plane Poi-seuille流的稳定性问题,求得临界雷诺数Rc=5772.2218,在雷诺数从Rc到R=1010范围内较精确地计算了该流体的中性曲线。 相似文献
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(王发民)(赵烈)(于欣)STABILITYSTUDYOFANUNSTEADYOSCILLATIONFLOW¥WangFamin;ZhaoLie;YuXin(InstiluteofMechanics.AcademiaSinica.Beijing100... 相似文献
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An investigation is described for instability problem of flow through a pipe of circularcross section.As a disturbance motion,we consider an axisymmetric nonlinear mode.Anassociated amplitude or modulation equation has been derived for this perturbation.Thisequation belongs to the diffusion type.The coefficient of it can be negative with Reynoldsnumber increasing,because of the complex interaction between molecular diffusion andconvection.The negative diffusion,when it occurs,causes a concentration and focusing ofenergy within the decaying slug,acting as a role of reversing natural decays. 相似文献