Chaotic flow in multiphase asymmetric stirring reactor revolutionizes oxygen mass transfer for non‐Newtonian fluid

Oxygen mass transfer in non‐Newtonian fluids represents a key rate‐limiting step in aerobic biopolymer fermentations. To enhance mass‐transfer performance, a novel chaotic reactor (CHR) featuring tri‐axial impellers was proposed and optimized using validated computational fluid dynamics (CFD) modeling. The impacts of pumping mode, impeller rotational speeds, and chaotic flow characteristics on the volumetric mass‐transfer coefficient ( k L a ) and power consumption ( P ) were systematically investigated. The CFD model demonstrates average relative deviations of 5.7% and 12.6% in predicting bubble coalescence/breakup behavior and k L a ‐ P relationships. The optimized CHR, configured with down‐pumping operation for both bottom and top pitched‐blade impellers, achieved 131% higher process efficiency than that of the conventional coaxial reactor when processing 1.0% carboxymethyl cellulose solution. The mechanism is attributed to the formation of a large‐scale horizontal vortex and effective chaotic flow at Reynolds numbers ( Re ) exceeding 17.5. These findings provide new insights for rational optimization in aerobic bioprocess fermentations.