

MATHEMATICAL MODELING OF THE BOILING PROCESS IN WEIGHTLESSNESS
doi:10.23877/MS.TS.23.011
Sapozhnikov V.B.^{1}, Korolkov A.V.^{2}
^{1} JFC "EKA", Korolev, Russia ^{2}STIC "EDUCON", LTD, Yubuleyny, Russia
Citation:
Sapozhnikov, V.B. and Korolkov, A.V., (2015) Mathematical modeling of the boiling process in weightlessness, Modern Science: Researches, Ideas, Results, Technologies, Iss. #1(16), PP. 61  66. doi: 10.23877/MS.TS.23.011.

Keywords: mathematical modeling; real zerogravity conditions; boiling of liquid; nucleate boiling 
Abstracts:
By the methods of mathematical modeling with computational experiment, research processes of liquid boiling in complete weightlessness are conducted with the aim to confirm the scientific hypothesis of the existence of nongravitational mechanisms of a steam bubble separation from the surface of a heater. It is known that in the terrestrial conditions, and in the conditions of reduced intensity of the field of the mass forces, boiling crisis occurs when the intensity of vaporization is so high that the flow of steam impedes the liquid supply to the heater surface. This phenomenon is quantitatively well described by the Kutateladze formula or other formulas that connect critical heat flux with the value of the gravitational acceleration g. The basis of this connection is a KelvinHelmholtz instability mechanism (Zuber explanation) within the process of interaction of a vapor domain and a liquid flow, generated by the buoyancy force (the RayleighTaylor instability). In weightlessness conditions RayleighTaylor mechanism of liquid flow formation is absent and for the supply of liquid to the heater surface an inertial motion of liquid, generated by the vapor pressure in the bubble, and pulling the bubble away from the heating surface, becomes responsible. It is shown that in the reduced gravity conditions with a decrease in intensity of the field of the mass forces, the role of inertial forces caused by the vapor pressure of the bubble increases. Confirmation of the hypothesis opens the possibility of realization of bubble boiling condition in complete weightlessness and the possibility of an effective heat exchange devices for the space flight conditions, based on phase transitions, development. 
References:
Korolkov A.V., Savitchev V.V. On LiquidGas System Behavior in the Variable Field of Acceleration Vector. Nongravitational mechanism of convection and heat/mass transfer. International Workshop. Abstract. September 1517, 1994. Zvenigirod, Russia, p 910.
Merte, H. Jr., Lee, H.S., at al., Hucleation, Bubble Growth and Heat Transfer in Extended Microgravity Pool Boiling. Proceedings of the Joint Xth European and VIth Russian Symposium on Physical Sciences in Microgravity, Vol 1, Moscow, 1997, p 354365.
Korolkov, A.V., Sapozhnikov, V.B., Tsherkasov, I.L. On the formulation of groundbased experimental studies of the formation of vapor bubbles in weightlessness // Abstracts XXXVII readings devoted to the development of scientific heritage and the development of the ideas of K.E. Tsiolkovsky. Kaluga: Vol. "Eydas", 2002,  p. 154.
Korolkov, A.V., Sapozhnikov, V.B., Separation of gas from liquid in the flow of gasliquid mixture in a zero gravity environment, with the help of combinedporous mesh material // Modern science: researches, ideas, results, technologies. Issue 1(14).  Dnepropetrovsk: "NPVK Triakon", 2014. p. 6065.


