Author, institution: Raminta Skvorčinskienė, Kaunas University of Technology
Science area, field: Technological Sciences, Energetics and Power Engineering – 06T
The Doctoral Dissertation is available at the library of Kaunas University of Technology (K. Donelaičio St. 20, Kaunas).
Scientific Supervisor: Prof. Dr. Habil. Jonas GYLYS (Kaunas University of Technology, Technological Sciences, Energetics and Power Engineering – 06T).
Dissertation defence board of Energetics and Power Engineering Science Field:
Prof. Dr. Habil. Eugenijus UŠPURAS (Lithuanian Energy Institute, Technological Sciences, Energetics and Power Engineering – 06T) – Chairman;
Prof. Dr. Habil. Vytautas MARTINAITIS (Vilnius Gediminas Technical University, Technological Sciences, Energetics and Power Engineering – 06T);
Dr. Raimondas PABARČIUS (Lithuanian Energy Institute, Technological Sciences, Energetics and Power Engineering – 06T);
Prof. Dr. Liudas PRANEVIČIUS (Vytautas Magnus University, Physical Sciences, Physics – 02 P);
Prof. Dr. Habil. Stasys ŠINKŪNAS (Kaunas University of Technology, Technological Sciences, Energetics and Power Engineering – 06T).
Official Opponents:
Dr. Habil. Algirdas KALIATKA (Lithuanian Energy Institute, Technological Sciences, Energetics and Power Engineering – 06T);
Prof. Dr. Gvidonas LABECKAS (Aleksandras Stulginskis University, Technological Sciences, Energetics and Power engineering – 06T).
Annotation:
The Leidenfrost effect was called after the scientist Johann Gottlob Leidenfrost in 1756. The effect occurs when the surface dries out and covers in steam layer (film). The earlier researchers mainly studied the processes that occur on heat transfer surfaces and liquid before the prevalence of critical heat flux. Boiling crisis is an extremely important factor, which occurs in the nuclear reactors during the cooling process. After studying the processes that happen during the boiling crisis (the change in friction between the body and steam film, the effect of rapidly changing environment’s temperature on the cooling body and others), it would be easy to manage the critical situation and know how to act if these limits are exceeded. Another alternative for the application of the second degree boiling crisis would be the reduction of friction for the body which moves in the water. In the thesis, it has as well been attempted to determine the impact of Leidenfrost effect on the change of moving body’s velocity. The object of this research is to get acquainted with the second level boiling crisis that it would be possible to control it after surpassing the critical values and prove the body movement advantage (in terms of velocity) with lower energy consumption if this effect is applied. This work contains experiments with spherical bodies of different materials (steel, copper, aluminium) in order to examine the effect of the material on heat exchange processes and the peculiarities of cooling dynamics.
The work provides the following:
