arXiv subjects

Petr A. Skovorodko

Publications and source records attributed to Petr A. Skovorodko.

4 recordsLinked to original sources

arXiv2004

Semi-empirical boundary conditions for strong evaporation of a polyatomic gas

Semi-empirical procedure of obtaining the boundary conditions for strong evaporation of a polyatomic gas from a plane surface is proposed. The procedure is based on specifying the dependencies of specific momentum and enthalpy of the flow from the gas flow rate. The latter are derived from the analysis of the available data concerning the evaporation of polyatomic and monatomic gases. The procedure predicts the exactly sonic terminal velocity of the flow and leads to some corrections of existing boundary conditions in transonic region. Thus, for j = 2 and sonic flow the corrections for pressure, temperature and fraction of back-scattered molecules are about 0.7%, -3% and -8%.

physics.flu-dyn↗

arXiv2004

Angular momentum conservative algorithm of collisional process in DSMC method

The traditional algorithm of collisional process in DSMC method, used for calculation of velocities of molecules after collision, is based on the conservation laws for linear momentum and total energy. This algorithm does not provide conservation of angular momentum with respect to some axis, but for non-rotating flow this circumstance is insignificant, since the mean value of angular momentum of such kind of flow is equal to zero. The situation changes for axisymmetric flow with rotation. In this case the traditional procedure leads to some internal source or sink of angular momentum that may distort the flowfield. In the paper the discussed effect is recognized and investigated. The angular momentum conservative (AMC) algorithm of collisional process is proposed.

physics.flu-dyn↗

arXiv2004

Some features of the flow in the Holweck pump

Numerical algorithm for direct simulation of the gas flow in the Holweck pump is developed. The results illustrating the important features of the flow in the pump are reported. An attention is paid to the problem of the pump design optimization.

physics.flu-dyn↗

arXiv2004

Continuum model for Couette-Poiseuille flow in a drag molecular pump

A continuum one-dimensional model of the plane Couette-Poiseuille flow is developed to describe the pressure distribution in a drag stage of molecular pump of either the Gaede or Holweck type. In spite of its simplicity and approximate nature the model provides a good qualitative representation of the drag pump operation in the whole range of the regimes from the continuum to free molecular ones.

physics.flu-dyn↗