Issue 1/2011

ABSTRACTS:

UDK 517.9+519.6+533
MECHANICS VARIATIONAL PRINCIPLES APPLICATION TO CONSTRUCT TIME DISCRETE GAS DYNAMICS DIFFERENCE MODELS. 7.  CONSERVATION OF PHASE VOLUME AND CANONICITY IN FINITE-DIFFERENCE SCHEMES OF “CROSS”-TYPE / Yu. A. Bondarenko // P. 3
Conservation of phase volume and canonicity (hamiltonicity) is proved for finite-difference schemes of Lagrangian gas dynamics constructed with variational stepwise method for which time and space discrete statement of Hamilton-Ostrogradsky principle of least action is used. Canonicity conservation is valid in certain cases only for complex “implicit” impulses.
Key words: Lagrangian gas dynamics, principle of least action, variational difference schemes, difference schemes of “cross”-type, phase volume, canonicity.

UDK 519.245+539.12
C-007 TECHNIQUE USING MONTE-CARLO METHOD OF COUPLED LINEAR EQUATIONS OF NEUTRON, GAMMA-QUANTUM, ELECTRON AND POSITRON TRANSFER / А. К. Zhitnik, Е. N. Donskoi, S. P. Ognev, A. V. Gorbunov, A. N. Zalyalov, N. V. Ivanov, A. G. Mal’kin, V. I. Roslov, Т. V. Semenova,  A. N. Subbotin //  P. 17
C-007 technique is described for Monte-Carlo linear problems of consistent transfer of neutrons, gamma-quantum, electrons and positrons.
Key words: Monte-Carlo method, linear equation of particle transfer.

UDK 519.6
PECULIARITIES OF TVD-APPROACH TO DSn-METHOD OF 3D EQUATION OF NEUTRON TRANSFER IN CURVILINEAR COORDINATE SYSTEM / A. P. Arsentiev, V. N. Pisarev // P. 25
Considered here are certain peculiarities of non-linear TVD-scheme application for 3D time-dependent equation of neutron transfer in curvilinear coordinates. The scheme constructed with DSn-method modification based on TVD-methodology, retains the main advantages of  DSn-method: upper time layer is approximated within the counting cell, cost effective sweep method is used for difference equations. Given here are the numerical results.
Key words: transfer equation, TVD-method, DSn-method.

UDK 517.956
HEAT WAVES FROM POINT AND VOLUME SOURCES IN 2D AXISYMMETRIC AND PLANE DOMAINS / P. I. Pevnaya, B. P. Tikhomirov // P. 40
Considered here are some simple conjugated problems of nonlinear heat conductivity in heterogeneous medium with energy sources. The problems have exact solutions and can be used to validate the computational techniques and programs. The computational results are given for 2D axisymmetric problems using difference method with four-way run scheme. 
Key words: nonlinear heat conductivity, conjugated problem, spherical, cylindrical and plane waves, compound solution in 2D domains, test problems.

UDK 519.6
ON “STAGGERED ORDER EFFECT” IN CERTAIN DIFFERENCE SCHEMES FOR 2D AND 3D HEAT CONDUCTIVITY / Yu. А. Bondarenko, A. A. Golubev, А. А. Gorbunov,      А. О. Naumov, А. I. Panov // P. 49
Shown here is the staggered order effect producing capacity in certain schemes used for 2D and 3D heat conductivity computations. It takes place when temperature difference gradient derived from formulas similar to pressure gradient computational method in Lagrangian difference schemes, is used for approximation of flows across the edges. In point source problems, the main interaction in square and cube grid is diagonal. Described here is the way to avoid the staggered order effect. 
Key words: radiative heat conductivity, temperature difference gradient, regular and irregular grids, test computations.

UDK 519.6
PARALLELIZATION METHODS OF 2D HYDROCODE MEDUZA ON UNSTRUCTURED GRIDS WITH VARIABLE TOPOLOGY / V. A. Pronin // P. 54
Described here are parallelization methods used for gas dynamics problems on unstructured grids. Much attention is directed to parallelization grid algorithms. Computational results of the test problem verify the developed methods validity.
Key words: parallelization methods, unstructured grids, grid correction, MEDUZA technique.

UDK 004.514:004.045:004.4’2
UNIVERSAL SHELL PROGRAM TSS3 FOR USER INTERFACE CONSTRUCTION OF SOFTWARE SYSTEMS IN FORTRAN / N. А. Krut’ko // P. 68
Considered here are peculiarities and concept of TSS3 universal shell program of automated user interface construction of software systems in Fortran. It is based on object description of input data structure converted into user interface over formulated principles of conformity and integration of visual element editing. TSS3 shell has variable possibilities of editing facility dynamic control, and supports data visualization at the computation stage.
Key words: data structure, object approach, user interface.

UDK 539.3
SEMITHEORETICAL ANALYSIS OF THERMOPHYSICAL PROPERTIES OF MATERIALS AT INHOMOGENEOUS HEATING / N. I. Obodan, N. А. Guk, A. G. Patsyuk // P. 81
Considered here are identification method and algorithm of thermophysical properties of materials at inhomogeneous heating according to experimental results. It is suggested to define the unknown characteristics of material according to inverse heat conductivity problem. The suggested approach allows definition of the parameters under conditions of essential inhomogeneity of temperature field.
Key words: identification, thermophysical properties of material, heterogeneous heating, experiment, finite element method.

Reference data about the authors