Variations of rotating tank experiment for geophysical fluids research and education

Despite progresses in computational science, laboratory experiments remain useful for geophysical fluid dynamical research and especially for education. This presentation summarizes the development of a 14-inch rotating fluid tank at Arizona State University and the adventures that came with it. It is shown that a classical zonally symmetric rotating tank can be modified to perform experiments with a zonally asymmetric pole-to-equator temperature gradient. Using the modified setup, a laboratory realization of a thermally forced quasi-stationary long wave will be demonstrated. Parallel to the development of the rotating tank, numerical modeling of the laboratory flow has been carried out using Ansys-Fluent, a commercial computational fluid dynamics (CFD) solver commonly used in engineering applications. Under a closed-lid condition, the simulations reproduced several flow regimes that resemble the experiments. The CFD simulation became more complicated under a realistic setting with open water. Such a case involves modeling a system of two fluids (water and air) and the dynamics of their interface. The development of that type of simulation is underway. While numerical simulation cannot completely replace the experiment, we hope to use the CFD solver to perform assessments for the future design and improvement of the laboratory experiments.