Signal of punched rigid-flexible combination impeller disturbance of oil-water biphase pressure fluctuation in the mixer-settler were collected and processed by LabView

plus Matlab software. The largest Lyapunov exponent (LLE) and multiscale entropy (MSE) reflected the degree of the chaos in the fluid field. At the same time

the fluid field's visualization technology was adopted to observe fluid mixing performance. It indicated that compared with the rigid combination impeller

with utilizing punched rigid-flexible combination impeller

the fluid field's structure

coupled with the way of energy dissipation was controlled by the synergetic effect of punch hole and flexible impeller. Furthermore

the chaos of fluid and mixing performance were superior to the rigid combination impeller. At rotation speed 88 r·min-1

the chaotic mixing of fluids was at the optimal state

and the LLE was over zero

testifying the fluid mixing system in chaotic state. Punched rigid-flexible combination impeller system of MSE was significantly higher than that of the rigid combination impeller

indicating mixing performance of punched rigid-flexible combination impeller superior to the rigid combination impeller system. The number of punched holes on the flexible and the thickness of flexible blade had obvious influence on the chaotic mixing performance.