Solving Problems Arising during the Monocrystals Growth in Microgravity Using Controlled Vibration

Abstract

Earlier studies of the vibration effect on a vessel with a fluid with gas bubbles dissolved in it permitted to establish the localization and stable position of the "swarm" of gas bubbles at a certain level of fluid in the vessel, corresponding to a certain frequency and vibration acceleration, as well as the volume of the "swarm" of gas bubbles. Controlling the "swarm" of gas bubbles in a fluid by changing vibration frequency at constant vibration acceleration has been proven. The study showed that at a certain frequency and vibration acceleration of vibration, a resonant phenomenon – vibroturbulization occurs, in which the air above surface of fluid in a vibrating vessel takes an active part and which is characterized by intensive mixing, if the fluid is two or more immiscible fluids, of these fluids and the formation of a homogeneous mixture. The paper presents a theoretical and experimental study of the behavior of a "swarm" of gas bubbles dissolved in a fluid and of air above surface of fluid in a vibrating vessel under vibration impact in the acoustic range of 40 - 400 Hz at a constant vibration acceleration of 150 m/sec2 both in terrestrial conditions and in microgravity conditions. The new physical interpretation of previously obtained theoretical description of the behavior of air bubble or the "swarm" of gas bubbles dissolved in a fluid in a vibrating vessel under vibration impact in terrestrial conditions and experimental confirmation of the obtained theoretical results and further study of the stable control by gas bubbles dissolved in the water permitted to develop a new method of degassing of different fluids in terrestrial conditions.The theoretical and experimental study of behavior of air above surface of fluid in a vibrating vessel under vibration impact in the acoustic range in terrestrial conditions permitted to theoretically describe the process of vibroturbulization and calculate the operating parameters of this process confirmed by specially conducted experiments that led to the development of completely new methods of advanced foam materials, ceramic materials , composite and nanocomposite materials production, and method of biodiesel destruction prevention during storage and transportation. The results of conducted theoretical description and computer simulation of the behavior of gas bubbles dissolved in a vibrating fluid under conditions of an acceleration of gravity decrease and a theoretical assumption about the possibility of using of the process of vibroturbulization for intensive mixing of a fluid with its internal components in microgravity were confirmed during flight tests on the board of aircraft IL-76K that led to the development of completely new method of degassing of fluid fuel in the fuel tank of a rocket engine and special fluids in the life support system of spacecraft during the space flight and method of intensive mixing of the melt or crystalline solution components in microgravity for unique homogeneous crystal growth in the space flight.