论文标题
自诱导的瑞利 - 泰勒在隔离干燥颗粒流中的不稳定性
Self-Induced Rayleigh-Taylor Instability in Segregating Dry Granular Flows
论文作者
论文摘要
流向粗糙倾斜的干燥颗粒材料会经历自我诱导的雷利 - 泰勒（RT）不稳定性，然后自发出现对流细胞。为此，颗粒的大小和密度不同，较大的颗粒是较密集的，但仍向表面隔离。当流动与往常一样，最初由两个层的密集颗粒制成时，在流动过程中会形成瑞利 - 泰勒的不稳定性。当流量最初是由一个均匀层混合物制成的时，颗粒隔离会导致在表面上形成不稳定的大密度颗粒层，随后以RT羽流模式不稳定。不稳定的密度梯度仅由颗粒物的运动引起。使用两种不同的方法，实验和模拟研究了这种自我诱导的雷利 - 泰勒不稳定性和两层RT不稳定性。最后，与通常的流体行为相反，RT不稳定性在两个叠加的稳定稳定层中放松，颗粒流变成了与雷利-b {é}相似的循环细胞相关的交替带的模式，使分离持续性运动。
Dry granular material flowing on rough inclines can experience a self-induced Rayleigh-Taylor (RT) instability followed by the spontaneous emergence of convection cells. For this to happen, particles are different in size and density, the larger particles are the denser but still segregate toward the surface. When the flow is, as usual, initially made of two layers, dense particles above, a Rayleigh-Taylor instability develops during the flow. When the flow is initially made of one homogeneous layer mixture, the granular segregation leads to the formation of an unstable layer of large-dense particles at the surface which subsequently destabilizes in a RT plume pattern. The unstable density gradient has been only induced by the motion of the granular matter. This self-induced Rayleigh-Taylor instability and the two-layer RT instability are studied using two different methods, experiments and simulations. At last, contrarily to the usual fluid behavior where the RT instability relaxes into two superimposed stable layers of fluid, the granular flow evolves to a pattern of alternated bands corresponing to recirculation cells analogous to Rayleigh-B{é}nard convection cells where segregation sustains the convective motion.
