Characterization of Multiphase Systems in Process Engineering by the Investigation of Their Thermophysical Properties

Multiphase systems can be found in many fields of process engineering such as catalysis, separation technology, and heat engineering. For the design of corresponding processes and apparatuses, but also for a fundamental understanding of the fluid behavior, knowledge of the thermophysical properties in multiphase systems is necessary. To date, research on the transport and interfacial properties of multiphase systems, especially dispersions with a continuous liquid phase and systems with two or three separated phases, is often sparse and/or inconsistent. The present habilitation thesis outlines scientific advancements in the characterization of multiphase systems via the investigation of their thermophysical properties. Results are shown and discussed for the effective thermal conductivity of dispersions with a continuous liquid phase in the form of nanofluids and microemulsions as well as for the viscosity and interfacial tension of vapor-liquid and vapor-liquid-liquid systems. Not only contributions are made to a reliable experimental database for the studied thermophysical properties of technically relevant working fluids, but the further development of experimental and simulation methods for studying such systems is also realized, in particular with respect to surface light scattering. Relationships between the macroscopic thermophysical properties and the fluid structure in the bulk and at the interface are drawn, which partly serve to develop prediction or estimation models for engineering purposes.