Sorokina T. Instability of steam bubble and heterogeneous of flows in processes of discrete-pulse power input.

Instability of processes and objects during realization of a principle of discrete-pulse energy input (DPEI) was studied in the dissertation. An instability analysis of the working element of DPEI (steam bubble) and stream of a liquid in processes and appara-tuses DPEI was conducted. As a result of the research of the steam bubble instability, the criteria of monotonous and oscillating instability were obtained, that allowed to analyze the nature of influence of different factors on the instability of the examined element of DPEI. Behavior of the amplitude and frequency characteristics of a steam bubble taking into account effects of viscosity, surface-tension, overheat of the liquid, different rheological laws of the medium and magnetic field was studied. Time of the bubble col-lapse was determined with allowance for the surface-tension and viscosity effects. Hydrodynamic instability of flow at the combined influence of different disturb-ing factors was explored, including effects of steam content, non-uniformity of the den-sity and viscosity distributions, centrifugal force and magnetic field. Investigation of the instability in non-Newtonian liquids was conducted. Practical aspects of the stability were considered, namely, hydrodynamic instability in the DPEI apparatuses such as ro-tor-pulse apparatus, pneumo-pulse apparatus and adiabatic boiling apparatus.