ELISA: A MONTE CARLO CODE FOR CALCULATION COMBINED PHOTON, ELECTRON АND POSITROH TRANSPORT

E.N. Dоnsкоу
VANT. Ser.: Mat. Mod. Fiz. Proc. 1993. No 1. P. 3-6.

      ELISA is a Monte Carlo code designed for a broad class oi photon, electron and positron transport problems. A system of linear time- dependent Boltzmann equations is solved involving spectral constants.
      Electron and positron transport equations use the catastrophic collision scheme that describes small-angle collisions in terms of Focker-Planck approximation. Computation efficiency increase methods and ELISA capabilities are examined.

G.P. Prокоpоv
VANT. Ser.: Mat. Mod. Fiz. Proc. 1993. No 1. P. 7-13.

      A technology is developed to calculate parametric square mapping on a variety of domains using a pair of elementary harmonic functions. Conditions for mapping univalency are studied and examples are given to illustrate its loss. A small number of control parameters allows to vary conveniently the domain geometries.
      A PC implementation of the algorithm can be used as a test problem generator for checking and comparing the methods for 2-D regular grid developments.

V.T. Zhuкоv, O.B. Feоdоritоva
VANT. Ser.: Mat. Mod. Fiz. Proc. 1993. No 1. P. 14-18.

      In this work the new discretization method of two-dimensional parabolic and elliptic differential equations is presented.
      This method is a special version of the well known balance method and can be applied for finite difference approximation equation in the region with curvilinear boundary and on the non uniform curvilinear meshes. For time-discretization of the parabolic equation we use the explicit-iteration scheme with Chebyshev parameters. This method may be generalized to the three-dimensional cane.

V.P. Gоrelоv, G.G. Farafоntоv
VANT. Ser.: Mat. Mod. Fiz. Proc. 1993. No 1. P. 19-23.

      Estimation procedure is proposed for energy dependence of a neutron flux in the layers of the multilayer Wigner-Seitz cell. The knowledge of this dependence is necessary to calculate group neutron constants of a heterogeneous reactor.

A.A. Shanin, Yu.V. Yanilkin
VANT. Ser.: Mat. Mod. Fiz. Proc. 1993. No 1.. P. 24-30.

      Critical points are given for construction of gasdynamic finite-difference Euler-variable schemes implemented within the EGAK complex. Difference schemes are intended for calculations of two-dimensional flows in a multicomponent medium (consisting of several materials each governed by its own equation of state) which are characterized by strong deformations. The concentration method is used to localize and to prevent the computational diffusion of contact boundaries. Computational results for several problems are given.

A.D. Gadzhiev, A.A. Shestакоv
VANT. Ser.: Mat. Mod. Fiz. Proc. 1993. No 1. P. 31-37.

      For some difference scheme from the ROMB parametric family, stability and convergence are shown in grid spaces L₂ and С when the energy equation and radiation transport time-dependent equation are solved together.
      The proof is given for the linear case where the inner material energy is proportional to the fourth power of temperature.

V.E. Shemarulin
VANT. Ser.: Mat. Mod. Fiz. Proc. 1993. No 1. P. 38-43.

      The linear differential operator la found that generalizes the operator called Darboux operator by the author which is well known in one-dimensional polytropic gas flow theory. The operator found relates linear equations obtained from equations of one-dimensional plane isentropic gas dynamics written in Eulerian and Lagrangian variables in the case of arbitrary equation of state using Legendre transformation. The problem of existence of a similar operator is solved for a special class of second order linear equations being natural generalization of linearized one-dimensional gas dynamics equations. The existence of all these operators is shown to be provided by the corresponding equations invariance with respect to transformations analogous to Galilean transfer.

G.I. Vоrоnоv, M.I. Kaplunоv, V.I. Klenоva, V.I. Legon´kоv, N.I. Leоnоva, V.A. Murashkina, A.T. Sapozhnikov, V.P. Sокоlоv, Z.V. Surayeva
VANT. Ser.: Mat. Mod. Fiz. Proc. 1993. No 1. P. 44-47.

      General structure and functional capabilities of unified system for computing thermodynamic functions of equations of state independent both on application program and computer type are described.

А.А. Коchubеy
VANT. Ser.: Mat. Mod. Fiz. Proc. 1993. No 1. P. 48-52.

      A finite-element algorithm is presented for calculation of flow and heat transfer parameters in complex shape channels with axially varying geometry (diffusor/confusor channels). Velocity and pressure fields are computed in channels.