Results

Theoretical framework

The bubble column operating curve

The theory interprets bubble column fluid dynamics through a single relationship Ω between the drift flux and the gas holdup, whose analytical form is built upon the flow regime transition points.

task#A.1

Regime taxonomy

Analytical formulation of the operating curve across mono-dispersed and poly-dispersed homogeneous regimes, transition regimes with and without coalescence-induced structures, and pseudo- and pure-heterogeneous regimes.

task#B.2

Variable drift-flux model

A variable-coefficient formulation of the Zuber–Findlay drift-flux model, linking each point of the Ω-curve to the corresponding regime’s global and local flow properties.

task#A.3

Mass transfer closure

Computation of the interfacial area along the operating curve, from which the CO₂ mass transfer rate is derived through mass-transfer models.

Experimental image analysis

Seeing the bubble scale

Liquid velocity fields
Liquid velocity fields — Particle Shadow Velocimetry resolves the liquid velocity field around individual bubbles, quantifying wake structures and liquid recirculation.
Bubble tracking in dense flows
Bubble tracking in dense flows — Automated image analysis identifies and tracks bubble trajectories, providing size, shape and velocity statistics near the gas sparger.