论文标题
液态金属旋转对流中的振荡热惯性流动
Oscillatory thermal-inertial flows in liquid metal rotating convection
论文作者
论文摘要
我们介绍了对流液体中的第一个详细的热和速度场表征对流的液体壳缸，该旋转圆柱缸具有与行星核心流体相似的热物理特性。我们的实验室实验和密切相关的直接数值模拟都在稳定对流模式发作之前在该方案中进行。这使我们能够研究稳定柱模式出现之前，在液体金属中发展的振荡对流模式，侧壁模式和宽带湍流。我们的热度测量结果表明，强烈的惯性，热风流，速度达到了可比的非旋转病例的速度。振荡性的对流和壁模式在我们广泛的实验中共存，以及斯特图尔森层中峰值的强层流，但在较高的超临界情况下，延伸到液体中深处。流动含有明显的时光螺旋性，在整个平面上是抗对称的，表明振荡性液态金属对流包含运动级发电机的运动学成分。
We present the first detailed thermal and velocity field characterization of convection in a rotating cylindrical tank of liquid gallium, which has thermophysical properties similar to those of planetary core fluids. Our laboratory experiments, and a closely associated direct numerical simulation, are all carried out in the regime prior to the onset of steady convective modes. This allows us to study the oscillatory convective modes, sidewall modes and broadband turbulent flow that develop in liquid metals before the advent of steady columnar modes. Our thermo-velocimetric measurements show that strongly inertial, thermal wind flows develop, with velocities reaching those of comparable non-rotating cases. Oscillatory bulk convection and wall modes coexist across a wide range of our experiments, along with strong zonal flows that peak in the Stewartson layer, but that extend deep into the fluid bulk in the higher supercriticality cases. The flows contain significant time-mean helicity that is anti-symmetric across the midplane, demonstrating that oscillatory liquid metal convection contains the kinematic components to sustain system-scale dynamo generation.
