Droplets behavior of subcooled dispersed phase under nucleate boiling of continuous phase of liquid emulsion

Significance 

Several industries such as metal processing, food and beverages and pharmaceuticals are characterized by using emulsions of immiscible liquids which pre-determines the efficiency and quality of their products. Unfortunately, current technology applications of emulsions of liquids in industries are associated with several drawbacks that impact negatively on the industrial processes, therefore, resulting in poor quality products. To this end, researchers have been looking for alternative methods of successful applications of an emulsion of immiscible liquids in industries by creating special units for forcing of interactions dispersed phase. It promotes to obtain the desired results and have identified prediction of suitable hydrodynamic conditions as new promising solutions.

Presently, thermal processes in emulsions with phase changes is studied not sufficiently deeply, that result to complexity in designing and operating the industrial equipment because an ambiguous behavior of the dispersed phase of emulsions. It is necessary to take into account in more detail the characteristics of heat transfer in a heterogeneous medium of the emulsion flow. Therefore, structural modeling representation of the behavior of boiling emulsions, which influence on effectiveness industrial technologies, is of significant practical and science importance. Detail specified models provide adequate description and representation of experimental results, unlike general analytical methods.

The reason for this is a large number of dimensional parameters and regimes heat transfer which involved in formatting of complex processes of boiling liquid emulsions in non-isothermal conditions. As structural elements have been used mechanisms of the elementary physical phenomena to purposefully represent composition of complex processes because they are much simple and accept theoretical models. In consequence of this, became possible enabled efficiently simulation of complex heat transfer in non-isothermal liquid emulsions and in particular consider the phase transitions in explicit form.

Generally, in the unstable emulsion the boundary between physical phenomena of the breakage and coalescence is defined by the maximum stable size droplets, which is resistant to breakage. Furthermore, it also takes into account influence hydrodynamic conditions on the mechanisms of such kinetic processes. Heat transfer in non-isothermal conditions complicates the interaction droplets of dispersed phase by expanding number of the mechanisms of the elementary physical phenomena resulting in hot turbulence due to the forced convection. The resulting pulsations in the emulsion flow not only stimulate heat transfer, but can also lead to the destruction of the droplets of the dispersed phase.

Professor Alexander Rozentsvaig and Dr. Cheslav Strashinskii at Kazan Federal University investigated the modeling representation of breakup processes of subcooled droplets of dispersed phases in emulsion volume in result of nucleate boiling of a continuous phase. The authors used the physical models in form of mechanisms of the elementary physical phenomena and the experimental data to evaluate the interrelation of mechanisms the hydrodynamic and heat transfer phenomena. Their work is published in the journal, International Journal of Heat and Mass Transfer.

The authors observed that boiling of the overheated continuous phase of liquid-liquid emulsions resulted in perturbations similar to the usual turbulence of homogenous liquid. The formation of vapor nuclei and subsequent growth of vapor bubbles influence on the hydrodynamic characteristics of boiling continuous medium. For instance, it turned out that the quality of metal processing was improved by 10-18% by controlling the conditions of dispersion of the emulsions under minimum quantity cooling lubrication.

Therefore, the developed model by Rozentsvaig and Strashinskii would be useful for expansions frameworks existing models about breakup of droplets under influence complex interconnected hydrodynamic and thermophysical processes in liquid emulsions. This will help to create optimal conditions for production and advance product quality in numerous industries.

Droplets behavior of subcooled dispersed phase under nucleate boiling of continuous phase of liquid emulsion - Advances in Engineering Droplets behavior of subcooled dispersed phase under nucleate boiling of continuous phase of liquid emulsion - Advances in Engineering Droplets behavior of subcooled dispersed phase under nucleate boiling of continuous phase of liquid emulsion - Advances in Engineering

About the author

Alexander Kurtovich Rozentsvaig is a Professor at the Kazan (Volga Region) Federal University, Naberezhnye Chelny Institute. In 1970 graduated from the faculty of mechanics and mathematics of Kazan state University, specialty “Mechanics” with specialization “Hydromechanics and Aeromechanics”. In 2005 he defended his thesis for the degree of doctor of technical Sciences: “Energy saving patterns in the transfer processes in complex disperse systems” on a specialty “Industrial heat power engineering”.

He does research in Fluid Dynamics, Applied Mathematics and Engineering Physics. His research interests lie in the field of hydrodynamics and heat and mass transfer of unstable and non-isothermal emulsions of immiscible liquids. They a systematic approach to the structuring of complex energy-saving structures of transport processes and modeling of mechanisms of interaction of elementary physical phenomena is developed. In particular, he studied on relationship of the basic physico-chemical phenomena in unstable emulsions: coalescence, breakage and sedimentation of droplets of dispersed phase and on how their properties can be employed by the different technological processes. Subsequently, they were supplemented by heat transfer phenomena in the emulsions of immiscible liquids, accompanied by boiling of the dispersed or continuous phase, depending on which of the superheated. Their current project is «Modeling of turbulent flows of liquid emulsions with phase changes through the mechanisms of the elementary physical phenomena». He has authored or coauthored more than 80 articles in peer-reviewed journals and in collections of scientific papers together with three books.

In 2016, he was awarded the gold medal and diploma of DIPLOMA DI MERITO European scientific industrial chamber, Brussels, Belgium for exceptional professional achievements. Reviewer of the journals Chemical Engineering Science, International Journal of Heat and Mass Transfer, Measurement of International Publisher Elsevier.

Profiles: ResearchRID, ResearchGATE, GoogleScholar.

About the author

Cheslav Stanislavovich Strashinskii associate professor at the Department of Physics at the Naberezhnye Chelny Institute of Kazan (Volga Region) Federal University. In 1978, he graduated from the Physics and Mechanics Department of the Leningrad Polytechnic Institute (now St. Petersburg State Polytechnic University named after Peter the Great) with a degree in Thermal Physics. In the same year he entered the postgraduate school at the same institute where he was engaged in research in the field of combustion and explosion physics, and graduated from it in 1982. In 1983 he defended his thesis and received the degree of Candidate of Technical Sciences in the specialty “Thermal Physics and Molecular Physics”.

During his time at the Naberezhnye Chelny Institute, he participated in the development and creation of a laser-Doppler anemometer, participated in the creation of an experimental set-up designed to study the flow of gas flows in an internal combustion engine using a laser-Doppler anemometer. Studies have been conducted to optimize combustion processes in the cylinder of an internal combustion engine. Now his main research interests lie in the field of hydrodynamics and heat and mass transfer of unstable and non-isothermal emulsions of immiscible liquids. He is the author or co-author of more than 50 papers.

Profiles: ResearchGATE, GoogleScholar.

Reference

Rozentsvaig, A., & Strashinskii, C. (2018). Droplets behavior of subcooled dispersed phase under nucleate boiling of continuous phase of liquid emulsion. International Journal of Heat and Mass Transfer, 125, 1274-1283.

Go To International Journal of Heat and Mass Transfer

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