Summary: On the basis of ground modeling, thermovibrational convective regimes similar to those observed in space experiments are obtained. Over a wide range of the problem parameters, the evolution of the flow pattern and the spatial-temporal flow characteristics are studied. The effect of the quasi-static microacceleration component on the microconvective-flow structure is investigated. The results presented agree well with the data of orbital experiments. They give a deeper insight into the role of thermovibrational effects under real weightlessness and resolve the contradictions that appeared in the analysis of the onboard experimental data.