Bubbles in Polymeric Liquids: Dynamics and Heat-Mass Transfer

From the Authors' Preface The advancements of technology . . . and chemical engineering have brought about extensive use of a wide range of rheologically complex materials, e.g., polymeric solutions and melts, suspensions, mixtures, oil products, fibre-forming substances, etc. that are characterized by diverse and, every so often, significant deviations from classical Newtonian behavior. Such materials are often used in conditions where the formation of vapor-gas bubbles or two-phase flow regimes is possible. This necessitates deep investigations into the thermo-hydrodynamic problems of liquids with bubbles for the case of a continuous phase with anomalous rheological properties. These conditions are typical of a number of applications and manufacturing processes, e.g., gas removal from polymeric solutions or melts in production of film, chemical fibres and other polymeric materials. . . . The bubbles containing gas or vapor-gas mixtures are often present in polymeric systems. This is because of a number of reasons, e.g., a low wettability of solid surfaces by polymers, the use of volatile solvents, abundance of vapor-gas nuclei, the capture of gas by porous or fibre-like polymeric particles during the polymer dissolution or melting, etc. Spontaneous evacuation of bubbles in polymeric media is usually complicated by a high viscosity of the liquid; therefore two-phase polymeric systems possess a higher sedimentation and aggregation stability than bubble mixtures in low-molecular-weight liquids. One of the main problems in the dynamics of vapor-liquid and gas-liquid systems is the investigation of heat and mass transfer and phase interactions in a liquid with bubbles. The decisive importance of this problem in the analysis of various aspects of the bubbly fluid behavior under diverse conditions, in particular, during a sound wave propagation, has given impetus to numerous researches. The current state of art in the investigation of Newtonian liquids with bubbles is described in voluminous literature. However, these problems have been much less studied for non-Newtonian systems. Behavior of bubbles in polymeric liquids is of great interest because of wide application in chemical technology. . . . In a number of processes connected with the application of polymeric fluids, the dynamic interaction of bubbles with liquid phase plays the key role. Such interaction in the case of a polymeric liquid phase are essentially influenced by the specific properties of macromolecular fluids, including primarily the rheological effects. These effects in the bubble dynamics combined with heat and mass transfer between the bubble content and the ambient liquid constitute the main subject of the analysis presented in this book. Macrokinetics Laboratory, and Full Professor at the Byelorussian Polytechnic Institute, Department of Heat and Power Engineering. Dr. Schulman is recognized as a leading authority in his field of investigation. Extensive Bibliography: A valuable feature of this new book is its extensive international bibliography, with 393 references.

Table of Contents:
Transport Processes and Bubble Dynamics in Polymeric Liquid Physical Effects in Vapor-Gas Bubble Dynamics Rheology of the Liquid Phase Molecular Models and the Time-Temperature Superposition Principle Mass Transfer and Thermodynamics Properties of Macromolecular Solutions Heat and Mass Transfer in Vapor-Gas Phase Summary Rheological and Thermal Factors at Free Oscillations of Gas Bubbles The Rayleigh Problem Dissipative Losses at Bubble Oscillations in Liquid with One Relaxation Time Role of the Relaxation Spectrum Summary General Solution for Small-Amplitude Pulsations of Vapor-Gas Bubbles in a Relaxing Fluid The Temperature, Velocity and Pressure Fields in Liquid Phase Heat and Mass Transfer in Vapor-Gas Phase Conjugation of Solutions at the Interface Dissipative and Elastic Properties of Vapor-Gas Bubbles in Polymer Solution with Volatile Solvent Physical Parameters of the System Natural Frequencies and Damping of Free Oscillations Effective Dissipation Coefficient and Elasticity of Bubbles in a Sound Field Effects of Surface Activity Summary Rheological Non-Linearity and Dissipation in Centerline Phase Interactions Growth and Collapse of Bubbles in a Polymeric Liquid Rheological Non-Linearity and Heat Transfer Thixotropy Effects in the Bubble-Fluid Interactions Summary Growth of Bubbles and Vapor Films in Polymer Solutions Caused by Evaporation of Low-Molecular Solvent Thermal Stage of the Vapor Cavity Growth in Superheated Polymer Solution Evaporation of Solution Interacting with a High-Temperature Surface Summary Rheological Features and Heat and Mass Transfer at Sound Propagation in Polymeric Liquid with Bubbles General Physical Discussion Thermoacoustic Perturbations in a Collective of Bubbles Dispersion and Attenuation of Sound Waves Non-Linear Wave Equation for Relaxing Fluid with Gas Bubbles Equation of State for Bubble Mixture in Relaxing Fluid Wave Equation in the Boussinesque Approximation Structure of Stationary Shock Wave Burgers-Korteweg-de Vries Approximation Summary Experimental Results and Applications Dynamics of Individual Bubbles and Cavitation Boiling of Polymer Solutions Quenching of Polymeric Liquids Superheating and Ebullition of Polymer Solutions at Short-Term Intensive Heating