Thermocapillary Flow and Aggregation of Bubbles on a Solid Wall

Bubble separation and collision on thin wires during subcooled boiling

“…Sides and Tobias [13] discovered an aggregation mechanism of gas bubbles that they termed as ''specific radial coalescence. ' [14] suggested that thermocapillary flow around neighboring bubbles on a hot wall pulled the bubbles together by establishing a perpendicular temperature gradient, and the velocity is very small. This paper mainly presents experimental observations and associated theoretical analyses of bubble separation and collision phenomena during subcooled boiling on very thin heating wires.…”

Bubble dynamics during the non-isothermal degassing of liquids. Exploiting microgravity conditions

“…This motion in the present case is complicated by the existence of g-jitters and surface roughness which influences q. The gap between bubble and wall is of the order of micrometers [35] so even for a glass coated surface the roughness can influence the gap thickness and the bubble motion. Additional complication arises from the co-current growth of the bubble.…”

“…In [34], the flow and temperature fields around an immobile bubble attached to a heated wall are computed using multipole expansions and then the liquid entrainment and thermocapillary migration contributions are superimposed to give the bubble-bubble approach velocity. In a subsequent work, [35], the approach is improved adding a factor which hinders the motion of the bubble (with respect to that of the liquid) due to the existence of the solid wall. Good agreement between theoretical and experimental bubble approach velocities was found.…”

High-current density DC magenetohydrodynamics micropump with bubble isolation and release system

“…The collapse of the bubble aggregate further propels the fluid along the channel. In an open system, gas bubbles escape to the atmosphere rather than travel along with the fluid and aggregate along the walls due to thermocapillary effects (Kasumi et al 2000). Since the pump has to be hermetically sealed to prevent contamination for LOC application, a completely open micropump design is not an option.…”