The critical condition and oscillation – transition characteristics of thermocapillary convection in the space experiment on SJ-10 satellite

Abstract This paper is an investigation on oscillation characteristics and transition routes of thermocapillary convection in an annular liquid pool in the space experiment carried out on SJ-10 recoverable scientific experiment satellite. Thermocapillary convection caused by non-uniformity of surface tension and the instability problem of the convection are introduced, and the measurement by thermocouples has been analyzed in detail. Through the relationship between the critical condition of start-oscillation in thermocapillary convection and the volume ratio, and the relationship between the oscillation frequency and the volume ratio, transition processes from steady flow to oscillatory flow and then to bifurcation are investigated. In addition, the acting mechanism of thermocapillary force has been discussed comparing with buoyant-thermocapillary convection on the ground.