Inertial waves are oscillations in a rotating fluid that arise due to the restoring action of the Coriolis force. Low-frequency inertial waves are known to create columnar flow structures inrapidly rotating systems. Columnar heat transport away from the equator has been observed in some strongly forced, rapidly-rotating geodynamo simulations of the Earth’s core. In this study, we investigate the mechanism governing this heat transport by performing direct numerical simulations of model problems comprising buoyant blobs under rapid rotation in a periodic box. We consider a wide range of Rossby numbers (Ro), the ratio of advection to Coriolis force, and Peclet numbers (Pe), the ratio of thermal advection to thermal diffusion. Columnar flow structures, that comprise inertial wave packets, are observed to emerge from the buoyant regions and travel towards the box boundary. We find that the columnar heat transport occurs by advection governed by the local Pe (for instance, a larger vertical elongation in the blob is observed for larger Pe at the same Ro). The magnitude of the advection velocity is determined by the balance between the buoyancy and Coriolis forces. Moreover, the direction of advection is determined by the direction of the wave-induced flow in the columns above and below the blob. Our results suggest that the local Pe could be important for the columnar heat transport in strongly forced dynamo simulations.

惯性波是由于科里奥利力的恢复作用而在旋转流体中产生的振荡。已知低频惯性波会产生旋转流动的柱状流动结构。在一些强力的，快速旋转的地球核心的地震动模拟中，观察到了从赤道传出的柱状热。在这项研究中，我们通过对模型问题进行直接数值模拟来研究控制这种热传递的机制，这些问题包括在周期性框中快速旋转下的浮点。我们考虑了广泛的Rossby数（Ro），对流与科里奥利力的比值以及Peclet数（Pe），热对流与热扩散之比。观察到包括惯性波包的柱状流动结构从浮力区出来并向箱形边界行进。我们发现，柱状热传递是通过对流作用而发生的，该对流受局部Pe控制（例如，在相同Ro下，对于较大的Pe，在斑点中观察到较大的垂直伸长）。对流速度的大小取决于浮力和科里奥利力之间的平衡。此外，对流的方向由斑点上方和下方的列中的波诱导流的方向确定。我们的研究结果表明，当地Pe的 在强力发电机模拟中对柱状传热可能很重要。