Rayleigh-Benard对流中小扰动的发展及对流斑图

发布时间：2018-05-11 20:36

本文选题：混合流体 + Rayleigh-Benard对流　；参考：《应用力学学报》2016年06期

【摘要】：通过二维流体力学的扰动方程组的数值模拟,探讨了分离比ψ=-0.2时,长高比Γ=30的矩形腔体中混合流体Rayleigh-Benard对流发生点附近扰动的成长和斑图的形成。结果表明:温度场线性成长阶段扰动的成长率γ_m是相对瑞利数r的函数,成长率γ_m随着相对瑞利数r的变化关系式为γ_m=0.9351r~(5.2039);在对流发生点附近的瞬态斑图取决于相对瑞利数r。给出了不同的相对瑞利数r(r分别为1.5、1.7、1.8)的情况下从小振幅到大振幅稳定状态的过渡过程中的两种不同的对流斑图,并讨论了其动力学特性。研究发现,当r较大时,存在行波与定常波共存的现象。
[Abstract]:Based on the numerical simulation of the perturbation equations of two-dimensional hydrodynamics, the growth of disturbances and the formation of patterns near the Rayleigh-Benard convection point of mixed fluid in a rectangular cavity with a separation ratio of 蠄 -0.2 and a ratio of length to height 螕 ~ (30) are discussed. The results show that the growth rate of the disturbance in the linear growth stage of the temperature field is a function of the relative Rayleigh number r, and the relationship between the growth rate 纬 _ S _ m and the relative Rayleigh number r is expressed as 纬 _ m _ (0.9351R) 5.20390.The transient pattern near the point where the convection occurs depends on the relative Rayleigh number r. Two different convection patterns in the transition from small amplitude to large amplitude stable state with different relative Rayleigh number r = 1. 5 ~ 1. 7 ~ 1. 8) are given, and their dynamic characteristics are discussed. It is found that there exists the coexistence of traveling wave and steady wave when r is larger.
【作者单位】：西安理工大学西北旱区生态水利工程国家重点实验室培育基地;河南省开封市水利建筑勘察设计院;
【基金】：国家自然科学基金(10872164) 陕西省重点学科建设专项资金(00X901)
【分类号】：O35

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