Average Vibrational – Convective Fluid Flows in Two-Layer Systems of Different Permeability under Zero Gravity

Roll convection developed under vibrations in the two-layer fluid system with homogeneous porous zone of different permeability is investigated. The system performs high-frequency oscillations directed transversely to the vertical temperature gradient in weightlessness. The convection problem is simulated on the basis of the averaging technique. The ranges of vibration frequencies and permeabilities of the porous zone characteristic of the short- and long-wave rolls are determined. Under zero gravity, sharp change in the form of rolls occurring with increase in the permeability, which is typical for free thermal convection in layered systems under the ordinary Earth’s conditions, is revealed. The minimum Darcy number below which there is no sharp transition from short- to long-wave convection with increase in the vibration frequency is found.