Registration Number
0220U100260,
0117U000348
, R & D reports
Title
Statistical theory of condensation for realistic models of matter
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Head
Ushcats Mykhailo V., Кандидат технічних наук
Registration Date
14-01-2020
Organization
Admiral Makarov National University of Shipbuilding
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The object of study is the process of gas-liquid phase transition in atomic, molecular and ionic single-component fluids. The aim is to construct a general condensation theory based on the classical Gibbs statistics, which would allow determining the phase-transition parameters on the basis of information about the nature of intermolecular interaction. Methods of study are the cluster expansion for the partition function and equations of state in terms of reducible or irreducible cluster integrals, which remain applicable in dense states of fluid and condensation region. A complex technique has been developed to calculate high-order irreducible cluster integrals (viral coefficients) for variuos intermolecular interaction potentials, and an approximation of the entire infinite series of such integrals has been proposed. An efficient algorithm is developed to define the unlimited set of reducible cluster integrals on the basis of information about irreducible integrals. For a wide range of lattice-gas models, a general analytical expression is obtained for the phase transition activity (the convergence radius for the virial series in powers of activity). The lattice-gas saturation and boiling points are rigorously proved to be the points where the isothermal bulk modulus vanishes for the corresponding symmetric virial series. The issue on the density dependence of high-order cluster integrals has been investigated for the first time, and results made the behavior of the cluster expansion qualitatively adequate not only in gaseous but also in condensed states (including the phase-transition region). For various models of matter and even real fluids, approximation for reducible cluster integrals is proposed, which allows quantitatively adequate description of their behavior to the saturation point (inclusively), and, for lattice gas models, even at condensed states (including the boiling point).
Product Description
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Evfimko Kostyantyn D.
Bulavin Leonid А.
Mochalov Oleksander О.
Svechnikova O. S.
Sysoev Volodymyr M.
Ushcats Svitlana Yu.
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2020-04-02
