论文标题
垂直圆柱多孔平板中的浮力流和不稳定，具有可渗透边界
Buoyant flow and instability in a vertical cylindrical porous slab with permeable boundaries
论文作者
论文摘要
研究了边界温度差引起的垂直环形多孔通过中的基本固定浮力流。垂直的圆柱边界被认为是等温边界，并且对外部流体储层均可渗透。存在一个固定的平行速度场，流速为零和纯传导传热。其线性稳定性通过正常的压力和温度场的扰动分析。对流动不稳定性的过渡是由基本的水平温度梯度引起的。因此，它的性质与通常的雷利 - 纳德不稳定性不同。扰动流的线性动力学是通过数值解决的特征值问题的。它的解决方案在外部半径和内部半径之间的每个固定纵横比提供了中性稳定曲线。评估了不同纵横比的关键雷利数触发不稳定性的数量。结果表明，随着纵横比的增加，系统变得更加不稳定，当纵横比倾向于无穷大时，临界雷利数降至零。
The basic stationary buoyant flow in a vertical annular porous passage induced by a boundary temperature difference is investigated. The vertical cylindrical boundaries are considered both isothermal and permeable to external fluid reservoirs. There exists a stationary parallel velocity field with a zero flow rate and pure conduction heat transfer. Its linear stability is analysed with normal mode perturbations of the pressure and temperature fields. The transition to convective instability is caused by the basic horizontal temperature gradient. Hence, its nature differs from that of the usual Rayleigh-Bénard instability. The linear dynamics of the perturbed flow is formulated as an eigenvalue problem, solved numerically. Its solution provides the neutral stability curve at each fixed aspect ratio between the external radius and the internal radius. The critical Rayleigh number triggering the instability is evaluated for different aspect ratios. It is shown that the system becomes more an more unstable as the aspect ratio increases, with the critical Rayleigh number dropping to zero when the aspect ratio tends to infinity.
