Keywords: convection, Hele-Shaw cell, vibrations, numerical calculations, thermal measurements, seismic sensor.

Convective flows in a Hele-Shaw cell are investigated by experimental and theoretical methods when the cavity is heated from below and subjected to the influence of high frequency vibrations [1]. The methods of direct visualization with the help of video camera and thermal measurements have been used in experiments. Non-acoustic approximation is applied to calculate averaged convective flows and to analyze the scenarios of transition to chaotic regimes. The standard equation's system of thermovibrational convection describing the behaviour of averaged fields of velocity, temperature and pressure has been used to solve the problem [2]. The stability boundaries of mechanical quasi-equilibrium state, different stationary and time-dependent convective flows have been calculated numerically by the method of Galercin-Kantorovich and measured experimentally. The map of convective regimes on the plane of thermal and vibrational Rayleigh numbers has been received as a result.

Thus, there is following sequence of regimes for moderate values of vibrational Rayleigh number: mechanical quasi-equilibrium, stationary one-vortex flow, stationary two-vortices flow, stable pulsational two-vortices regime, regular oscillatory four-vortices regime with periodical reunification of vortices and chaotic oscillatory four-vortices regime with stochastic reunification of vortices. The results of the theoretical research confirm experimental data.

The influence of short vibrational signals on convective flows of homogenous fluids in a Hele-Shaw cell has been investigated theoretically. The cavity is heated from below by dotted thermopile. The temperature and velocity fields are calculated numerically by the method of finite differences in the cases of vertical and horizontal vibrations. The results of calculations are used to design sensors that have been intended for registration of low-frequency microaccelerations of the seismic origination. Working liquid has been selected and optimal aspect ratio of the cell sides is found on the base of numerical modeling.

1

V.A. Demin, G.Z. Gershuni, I.V. Verkholantsev, "Mechanical quasi-equilibrium and thermovibrational convective instability in an inclined fluid layer", Int. J. Heat Mass Transfer, v. 39, N 9, 1979-1991, 1996. doi:10.1016/0017-9310(95)00239-1

2

I.A. Babushkin, V.A. Demin, "Vibrational convection in the Hele-Shaw cell. Theory and experiment", J. of Applied Mechanics and Technical Physics, v. 47, N 2, 183-189, 2006. doi:10.1007/s10808-006-0041-0

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