Complexity Analysis of Bubble Plumes in Power Law Fluids Based on Chaos Theory

ABSTRACT In order to reveal the complexity of the internal flow of bubble plume in power law fluid, the flow characteristics and chaotic characteristics of plume are studied by experiment and theory. The chaotic characteristic parameters (correlation dimension D , K entropy, and Lyapunov exponent λ ) of gas velocity under different superficial gas velocities and liquid concentrations are analyzed. With the increase of superficial gas velocity and concentration of carboxymethyl cellulose sodium (CMC) aqueous solution, the values of chaotic characteristic parameters all increase. The rheological characteristics of the liquid phase have a significant effect on the flow field and chaotic characteristics. According to the power spectrum of velocity signal, the chaotic characteristics of the velocity are significant in power law fluid, and the energy of the flow field is high. The disorder of the gas phase becomes intense with the motion of the plume, and the energy of velocity signal increases. The complexity of gas–liquid two‐phase flow field was revealed, laying the foundation for the study of the flow mechanism of gas–liquid two‐phase flow.