Laboratory study of a steady‐state convective cyclonic vortex

Abstract

An experimental study of the steady-state cyclonic vortex from an isolated heat source in a rotating fluid layer is described. The structure of the laboratory cyclonic vortex is similar to the typical structure of tropical cyclones from observational data and numerical modelling, including secondary flows in the boundary layer. Different constraints of the steady-state hurricane-like vortex were studied. The three main dimensional parameters that define the vortex structure for a fixed geometry -heating flux, rotation rate and viscosity -were varied independently. Characteristics of the steady-state cyclonic vortex were measured experimentally for different values of kinematic viscosity (from 5 to 25 cSt), rotation rate (from 0.04 to 0.17 rad s −1 ) and heat flux (from 1 to 4.6 kW m −2 ). The crucial importance for the vortex formation has angular momentum exchange in the viscous boundary layer. It was shown that viscosity is one of the main parameters that define the steady-state vortex structure. Increasing the kinematic viscosity may substantially suppress the cyclonic motion for fixed values of buoyancy flux and rotation rate. Strong competition between buoyancy and rotation provides the optimal ratio of the heating flux and rotation rate for achieving a cyclonic vortex of maximal intensity. It was found that relatively small variation of the rotation rate for the fluids with low kinematic viscosity may remarkably change the cyclonic vortex structure and intensity.

Dependence of boundary layer thickness on layer height in laminar and transient convective regimes

“…In Rayleigh-Bénard convection the boundary conditions are defined using a constant temperature difference or heat flux. In the present configuration, that is often considered for laboratory modeling of geophysical flows [28][29][30][31][32] , the measurements of Nusselt number are more complex due to open surface of the fluid. Because of that the temperature at the top boundary depends on ambient conditions and it is unclear how q c should be evaluated.…”

Research in dynamic meteorology in Russia in 2015–2018

“…Таким образом, показатель IRE также связан с KSE. Исследования в [14] В цикле работ [16][17][18][19] экспериментально и численно изучалась конвекция над локализованным источником тепла в цилиндрическом слое для жидкостей с различными значениями числа Прандтля, в том числе и при наличии общего вращения жидкости. Структура воспроизводимого в лаборатории циклонического вихря подобна типичной структуре тропических циклонов по данным наблюдений и результатам численного моделирования, включая вторичные потоки в пограничном слое.…”