S. Gasiūnas “Investigation of interfacial shear in condensing steam-water flow through a horizontal channel” doctoral thesis defence

Author, Institution: Stasys Gasiūnas, Kaunas University of Technology

Science area, field of science: Technological Sciences, Energetics and Power Engineering, 06T

Doctoral Thesis was prepared externally.

Scientific adviser: Assoc. Prof. Dr. Raimondas Pabarčius (Kaunas University of Technology, Technological Sciences, Energetics and Power Engineering – 06T).

Dissertation Defence Board of Energetics and Power Engineering Science Field:
Prof. Dr. Habil. Gintautas Miliauskas (Kaunas University of Technology, Technological Sciences, Energetics and Power Engineering – 06T) – chairman,
Prof. Dr. Habil. Juozas Augutis (Vytautas Magnus University, Technological Sciences, Energetics and Power Engineering – 06T),
Dr. Algis Džiugys (Lithuanian Energy Institute, Technological Sciences, Energetics and Power Engineering – 06T),
Prof. Dr. Habil. Vytautas Martinaitis (Vilnius Gediminas Technical University, Technological Sciences, Energetics and Power Engineering – 06T),
Dr. Sigitas Rimkevičius (Lithuanian Energy Institute, Technological Sciences, Energetics and Power Engineering – 06T).

 The doctoral dissertation is available at the libraries of Kaunas University of Technology (K. Donelaičio St. 20, Kaunas) and Lithuanian Energy Institute (Breslaujos g. 3, 44403 Kaunas).

Annotation:

Not many experimental studies have been conducted in the two-phase stratified flow with condensation, and they are still in great demand for better understanding of the momentum and shear transfer between two phases and its influence to the turbulence.
In this work was determined the effect of condensation on the interfacial shear in the steam (4–8 m/s) and water (0–0.028 m/s) co-current flow in the horizontal rectangular channel with a length of 1.2 m, a height of 0.1 m and a width of 0.02 m. The established interfacial shear correlation can be used to improve numerical models of stratified condensing two-phase flow.
During the research it was contributed in the development of new Shear number Sn, and it was performed verification, based on mine and other authors’ experiments in two-phase flows. The design of systems and devices in which liquid and gas are flowing with great differences in velocity, it is necessary to know the flow regime, because the turbulence has a significant influence on the heat transfer. The new Shear number more accurately predicts the turbulence in liquid than Re, therefore Sn can be used in the field of thermal physics by analysing and designing two-phase non-condensing and most importantly condensing two-phase flows, such as heat exchangers, steam-water systems in industrial technological plants and their supply lines.