Numerical simulation of the flow stability in a high aspect ratio Taylor–Couette system submitted to a radial temperature gradient
Numerical simulation of the flow stability in a high aspect ratio Taylor–Couette system submitted to a radial temperature gradient
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DOI：
10.1016/j.compfluid.2014.05.025
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发表时间：
2014-09
影响因子：
2.8
通讯作者：
S. Viazzo;Sébastien Poncet
中科院分区：
文献类型：
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作者：
S. Viazzo;Sébastien Poncet
通过28次高阶数值模拟，研究了在一个服从径向温度梯度的高泰勒-库埃特装置(Γ=80，η=0.8)中，旋转引起的方位流和对流引起的轴向流之间的强烈竞争导致的不稳定性的形成。一种是探索丰富的过渡图，它报告了七种不同的流动模式，根据泰勒数和瑞利数的不同，显示为螺旋旋涡、波浪涡或两者的组合。Guillerm[1]实验观察到的部分螺旋区在很低的瑞利数下不能恢复。该研究较好地预测了初级不稳定性阈值附近不同螺旋线的时空性质，并对不稳定性的流动和热结构有了新的认识。最后，对于不同的Rayleigh数，建立了Nusselt数对Taylor数的分布。
From 28 high-order DNS computations, one investigates the formation of instabilities due to the strong competition between an azimuthal flow induced by rotation and an axial flow due to convection in a tall Taylor–Couette apparatus (Γ= 80, η= 0.8) submitted to a radial temperature gradient. One explores the richness of the transition diagram that reports seven different flow patterns appearing either as spiral rolls, wavy vortices or a combination of both depending on the Taylor and Rayleigh numbers. The partial spiral regime observed experimentally by Guillerm [1] is not recovered at very low Rayleigh numbers. The spatio-temporal properties of the different spirals close to the threshold of the primary instability are fairly predicted and a new insight on the flow and thermal structures of the instabilities is gained from this study. Finally, the distributions of the Nusselt number against the Taylor number are established for various Rayleigh numbers.