A genuine technological issue–the thermal convection of liquid in a rotating cavity–is investigated experimentally.The experiments are conducted within a horizontal annulus with isothermal boundaries. The inner boun...A genuine technological issue–the thermal convection of liquid in a rotating cavity–is investigated experimentally.The experiments are conducted within a horizontal annulus with isothermal boundaries. The inner boundaryof the annulus has a higher temperature, thus exerting a stabilising influence on the system. It is shown that whenthe layer rotation velocity diminishes, two-dimensional azimuthally periodic convective rolls, rotating togetherwith the cavity, emerge in a threshold manner. The development of convection is accompanied by a significantintensification of heat transfer through the layer. It is shown that the averaged thermal convection excitation inthe form of a system of two-dimensional rolls occurs against the background of oscillations of a non-isothermalfluid in the cavity reference frame caused by the gravity field. The excitation threshold and the structure ofconvective rolls are consistent with the results of the earlier theoretical studies by the authors performed usingthe equations of “vibrational” convection obtained by the averaging method. Furthermore, the experiments haverevealed a new type of averaged flow in the form of a spatially periodic system of toroidal vortices. It is shown thata steady streaming, excited by the inertial oscillations of the fluid, is responsible for the generation of the toroidalvortices. These flows develop in a non-threshold manner and are most clearly manifested in a case of resonantexcitation of one of the inertial modes.展开更多
基金supported by the Ministry of Education of the Russian Federation(Project KPZU-2023-0002).
文摘A genuine technological issue–the thermal convection of liquid in a rotating cavity–is investigated experimentally.The experiments are conducted within a horizontal annulus with isothermal boundaries. The inner boundaryof the annulus has a higher temperature, thus exerting a stabilising influence on the system. It is shown that whenthe layer rotation velocity diminishes, two-dimensional azimuthally periodic convective rolls, rotating togetherwith the cavity, emerge in a threshold manner. The development of convection is accompanied by a significantintensification of heat transfer through the layer. It is shown that the averaged thermal convection excitation inthe form of a system of two-dimensional rolls occurs against the background of oscillations of a non-isothermalfluid in the cavity reference frame caused by the gravity field. The excitation threshold and the structure ofconvective rolls are consistent with the results of the earlier theoretical studies by the authors performed usingthe equations of “vibrational” convection obtained by the averaging method. Furthermore, the experiments haverevealed a new type of averaged flow in the form of a spatially periodic system of toroidal vortices. It is shown thata steady streaming, excited by the inertial oscillations of the fluid, is responsible for the generation of the toroidalvortices. These flows develop in a non-threshold manner and are most clearly manifested in a case of resonantexcitation of one of the inertial modes.
