AN ADAPTIVE METHOD FOR NUMERICAL INTEGRATION OF HEAT-CONDUCTIVE MEDIUM EQUATIONS

A. V. Zabrodin, Ya. M. Kazhdan, T. Yu. Lutskaya, V. Yu. Meltsas, A. F. Nikulina, L. A. Pliner
VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1985. No 1. P. 3-12.

      An algorithm is proposed to numerically integrate media motion equations in terms of heat conduction. The algorithm ability to adequately reproduce the differential properties of a source computational problem is its special feature.

O.V.Buryakov, V.F. Kuropatenko
VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1985. No 1. P. 13-18.

      An exact solution was derived for a pistion motion problem in a two polytropic gas mixture based on local pressure components equilibrium hypothesis assuming the absence of interaction forces due to the component velocity differencies. The shock wave is determined by a combination of two great jumps with different propagation velocities. For a rarefaction wave, two types of solution were obtained: those with full and partial component separation near the piston.

V. K. Ladagin
VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1985. No 1. P. 19-25.

      Difference schemes for a numerical integration of Schrodinger-type equations are examined in terms of their dispersion properties. A possibility for developing high-order (6-and 8-order) dispersion schemes is shown. A comparison is made between difference schemes, including some numerical examples.

C. B. Alalykin, A. V. Zabrodin, F. S. Imshennik, Ya. M. Kazhdan, M. D. Churazov
VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1985. No 1. P. 26-42.

      А 1-D gas dynamics approximation is used to study a thermonuclear target ignition by compressing and heating it with heavy ion beams. The target consists of a gold sphere shell and DT fuel inside it. Radiant, electron (the so called a heat conduction) and neutron heating are taken into account.

V. A. Suchkov, V. N. Uvarov
VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1985. No 1. P. 43-48.

      A scheme is proposed for creating a utility system to solve time-dependent problems in mechanics of continuum which relies on inserting a standard time cut. Requirements are established for clit to define it as an internal one within the data conversion system. We focus on issues concerning grid-to-grid data reinterpolation. The system may be used for global grid changes when the program computes a problem or for transmitting data from one program to another to continue the computation. To illustrate this, numerical results for a 2-D gas dynamics problem are given.

E. R. Domilovsky, V. N. Piskunov
VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1985. No 1. P. 49-52.

      We analyze a block structure of a random mxn matrix, A, with r nonzero elements in the asymptotic limit, m, n → ∞, r(mn)^-1/2→τ. For τ = 1, a block is shown to occur having a dimension similar to that of the whole A matrix. We discuss the suitability of results obtained to study the block structure of incidence matrices in mathematical programming problems.

A. D. Gadzhiev, V. N. Pisarev, V. V. Rykovanova, A. A. Shestakov
VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1985. No 1. P. 53-65.

      The paper describes a new Romb method modification for solving a heat conduction equation. A modified scheme is flexible and monotonous and generalyzes to a 2-D case for solving a nonlinear heat conduction equation. The heat conduction equation solution by region runs using the Romb method is examined. The characteristics of the program implementing the numerical algorithm are briefly described.

T. P. Shevchenko
VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1985. No 1. P. 66-70.

      The RIF multiterminal system developed and running within the DIAPAK/BESM-6 OS, is presented. The system is an interactive facility for text processing (generation, editing etc.) and for transmitting batch jobs to be executed.
      In contrast with many multitermina1s such as DIMON, KRAB, MULTIDOSTUP etc. designed to operate with their own text archives, the RIF is completely compatible with the Dubna monitoring system in terms of external data (text) form stored.
      A general operation scheme is given along with the system-user interaction language.

A. S. Solntsev, Yu. V. Logvin, A. N. Solntseva, A. A. Minakova, Б. Р. Kiselev
VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1985. No 1. P. 71-74.

      Design concepts are given for the ES EVM direct-control interface lines dedicated to eight users. The switch developed and manufactured based on these concepts, establishes the communication between any pair of users. Both the ES processors and special peripherals may be users.

M. Yu. Kozmanov
VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1985. No 1. P. 75-77.

      A difference problem solution is proved to converge to a differential one for a class of nonlinear equation coefficients. A difference solution is derived using an implicit scheme which approximates a simulation system of transport equations. The scheme satisfies the maximum principle.

E. V. Groshev
VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1985. No 1. P. 78-82.

      The paper considers an iteration method for solving charged particle transport equations in a "cold” medium for a stationary case and a plane geometry. To increase the iteration process convergence rate a correction method is used which is based on determining a main error portion occurring within a simple iteration. The method permits to reduce the iteration number to a reasonable level (from 10 to 15 iterations). Numerical examples are given.

N. N. Abramov, B. P. Kiselev, A. S. Solntsev, V. I. Usov
VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1985. No 1. P. 83-84.

      The K565RU3A circuit time chart and the regeneration frequency were changed to increase the reliability of the ES-3266 computer solid-state memory. Some recommendations concerning the main memory repair are given. These activities allowed to increase substantially the ES-3266 reliability and the computer utilization.

V. G. Nikolaev
VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1985. No 1. P. 85-92.

      A method is described for solving three-temperature equations in gas dynamics. The method uses physical process splitting. The energy equation solution involves a multidiagonal run method which permits to solve the problem at this stage without splitting (the method is similar to that of matrix runs).
      For one-temperature heat conduction equations, a flow run version is developed which generalizes to a three-temperature case.

Yu. V. Logvin
VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1985. No 1. P. 93-95.

      The paper proposes a new hardware clock for the ES-2060 processor which is based on statistics accumulated in order to eliminate "false hangups" in the ES-4001 byte-multiplexed channel.