Thermocapillary instability of an infinite Prandtl number fluid with negligible gravitational effects

Summary Finite amplitude fluid motion is investigated in a horizontal layer of an infinite Prandtl number fluid with an upper free surface for the case where thermocapillary effects are significant and gravitational effects are negligible. It is found that subcritical instability exists and that two-dimensional rolls and down-hexagons (where motion is downward at the cells' centers) are always unstable. But up-hexagons (where motion is upward at the cells' centers) are stable for sufficiently small amplitude , while both uphexagons and squares are stable in a range of larger where hysteresis effects exist.With 1 Figure