M. Maziukienė “Modeling of complex heat transfer and phase change transitional processes of water droplets in humid air” doctoral dissertation defence

Author, Institution: Monika Maziukienė, Kaunas University of Technology

Science area, field of science: Technological Sciences, Energetics and Power Engineering, T006

Scientific Supervisor: Prof. Dr. Habil. Gintautas Miliauskas (Kaunas University of Technology, Technological sciences, Energetics and Power Engineering – T 006).

Dissertation Defence Board of Energetics and Power Engineering Science Field:
Assoc. Prof. Dr. Habil. Algirdas Kaliatka (Lithuanian Energy Institute, Technological sciences, Energetics and Power Engineering – T 006),  chairman,
Assoc. Prof. Dr. Jerzy Kowalski (Gdansk University of Technology, Poland, Technological sciences, Energetics and Power Engineering – T 006),
Prof. Dr. Gvidonas Labecas (Vytautas Magnus University Agriculture Academy, Technological sciences, Energetics and Power Engineering – T 006),
Dr. Raimondas Pabarčius (Kaunas University of Technology, Technological sciences, Energetics and Power Engineering – T 006),
Dr. Sigitas Rimkevičius (Lithuanian Energy Institute, Technological sciences, Energetics and Power Engineering – T 006).

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

Annotation:

Dissertation investigates the complex processes of water droplet heat and mass transfer. They are combined in a cycle of condensing, transitional evaporation and equilibrium evaporation regimes during the phase change which occurs on a droplet’s surface. The dynamics of a heated droplet’s surface temperature is directly related to the regimes. Stefan’s hydrodynamic flow influence is evaluated by the similarity theory based Spalding transfer parameter and its extension for the whole droplet phase transformation cycle is provided. The presented mathematical model and its development, as well as the numerical solution algorithm, do not contradict for provided droplet physical interpretation in the work which includes a droplet’s geometrical, thermal and energy state analysis. The definition of the flux dynamics near the droplet’s surface is based on a numerical iterative scheme which depends on the balance of the heat fluxes on the droplet’s surface. In the iterative scheme, the optimal parameters are outlined. In this scheme, the energy of the phase change and the external heat transfer are combined as well as the internal heat transfer which takes place in droplets. The results of the modeling conducted in this dissertation allow to achieve better understanding of complex transfer process in a consistently changing cycle of droplet phase transformation regimes. They also show the impact of radiation on the droplet’s thermal state and on the transitional evaporation regime.