


Since 1978 Published in Sarov (Arzamas16), Nizhegorodskaya oblast 
RUSSIAN FEDERAL NUCLEAR CENTER 
ALLRUSSIAN RESEARCH INSTITUTE OF EXPERIMENTAL PHYSICS 

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Issue N^{o} 3, 2012  THE MONOTONE PARTICLE METHOD FOR 2D GAS DYNAMIC FLOW SIMULATIONS
Yu. V. Yanilkin, V. A. Shmelev, V. Yu. Kolobyanin, S. P. Belyaev VANT. Ser.: Mat. Mod. Fiz. Proc. 2012. No 3. P. 314.
The article describes the development of the monotone particle method for 2D gas dynamic simulations implemented in the EGAK code. Algorithms of particle interaction with materials defined without particles, as well as algorithms enabling simulations, where particles are used only at interfaces are presented. Key words: gas dynamics, multicomponent media, monotone particle method, mixed cells, interface.
 PREDICTION OF EXASCALE COMPUTER SUBSYSTEM PARAMETERS Yu. G. Bartenev, Yu. A. Bondarenko, V. F. Spiridonov VANT. Ser.: Mat. Mod. Fiz. Proc. 2012. No 3. P. 1523.
Results of the analysis of relationships between parameters of exascale computer subsystems are reported. As a computing algorithm model we used explicit difference schemes for 3D gas dynamics problems. Assuming that the runtime of each problem in the entire computing field is the same, formulas for the growth of the interconnect bandwidth as a whole, memory size and memory speed at all tiers and performance of the graphics subsystem were obtained depending on the increase in the number of computing nodes (servers) and their performance for transition from an existing computer to a designed supercomputer. Application of these formulas enables balanced design of computers using performance parameters of existing computers, if their subsystem parameters are balanced. The results predicted by the formulas are shown to be close to the 2018 exascale computer performance predictions made by J. Dongarra. Methods and factors that in some sense simplify the design of such computers are described. Key words: supercomputer, computer parameters, computer scaling, interconnect bandwidth, speed and size of main and external storage, speed of graphics processing system, 3D nonsteadystate problems, explicit difference schemes.
 FINEGRAIN PARALLELING METHODS IN THE TIM2D CODE A. A. Voropinov, I. G. Novikov, S. S. Sokolov VANT. Ser.: Mat. Mod. Fiz. Proc. 2012. No 3. P. 2433.
TIM2D is a continuum mechanics simulation code, which uses arbitraryshape unstructured polygonal Lagrangian grids. Paralleling in TIM2D is provided at three levels: 1) paralleling in domains using an MPIbased distributedmemory model; 2) paralleling in paradomains, again using the MPI; 3) paralleling of computing cycle iterations using an OpenMPbased sharedmemory model. The article addresses finegrain paralleling algorithms (second level). These algorithms supplement the paralleling in domains and OpenMPbased paralleling implemented earlier. The finegrain paralleling can be done both with paradomain overlapping in one row of cells and without overlapping. The methods are compared in their paralleling efficiency using one of test simulations. Key words: TIM2D code, sharedmemory model paralleling, MPI, unstructured grids.
 MATHEMATICAL APPARATUS OF THE ISKENDER HARDWARE AND SOFTWARE PACKAGE V. M. Konyukhov, I. V. Konyukhov, S. V. Krasnov VANT. Ser.: Mat. Mod. Fiz. Proc. 2012. No 3. P. 3444.
The article describes the mathematical apparatus of the ISKENDER software and hardware package developed based on the methods of mathematical and numerical modeling of interrelated multiphase thermo and hydrodynamics processes occurring in directional well pipes, flow channels of submersible electrical centrifugal pumps and porous medium of complexstructure oil reservoirs. The package serves for the express analysis of operational conditions of production wells with vertical and horizontal ends, optimization of such conditions, maintenance of a databank on oil field and downhole equipment. Example simulations illustrating the performance of package modules are presented. Key words: mathematical apparatus, software package, numerical modeling, multiphase flow, oil reservoir, production well, electrical centrifugal pump, data bank.
 MODELING OF BINARY MELT CRYSTALLIZATION IN NUMERICAL AND EXPERIMENTAL BENCHMARKS S. M. Ganina, V. P. Ginkin, O. N. Budenkova, B. Saadi, L. Ashani, I. Fotrel VANT. Ser.: Mat. Mod. Fiz. Proc. 2012. No 3. P. 4556.
Computer modeling of a 2D numerical and a quasi2D experimental binary melt crystallization benchmarks was done. Results of the numerical benchmark simulations done with the FLUENT and GIGAN sowtware were compared. Impurity segregation results are in both qualitative and quantitative agreement. Results of numerical simulations of recrystallization of a rectangular SnPb ingot are presented. The simulations were done with the GIGAN software using two crystallization models  the equilibrium and the nonequilibrium one. The comparison of experimental and numerical data shows that the evolution of the temperature field driven by natural convection and impurity distribution in the crystallized specimen are better described by the nonequilibrium crystallization model. Key words: crystallization, binary melt, macrosegregation, phase diagram, twophase zone, convection, heat and mass transfer, columnar to equiaxial transition (CET).
 NUMERICAL MODELING OF A SERVER CABINET STRUCTURE WITH A NOZZLE TO PROVIDE UNIFORM DISTRIBUTION OF INCOMING COOLING FLOW E. G. Baikov, Yu. N. Deryugin, S. A. Levkin, S. M. Ustinov, A. A. Kholostov VANT. Ser.: Mat. Mod. Fiz. Proc. 2012. No 3. P. 5763.
The article describes design features and the cooling system of a new server cabinet design with an inclined prismatic nozzle, which provides uniform distribution of the incoming cooling air flow all the way along the cabinet height and high packing density. This design solution is one of RFNCVNIIEF promising projects related to the development of HPC systems. The article describes the technique, used as a basis for numerical simulations of the inclinednozzle server cabinet by solving the problem of heat transfer in solidstate structures with convective heat exchange, and implemented in the LOGOS software package. Results of numerical simulations are presented and compared with experimental measurements. Key words: heat conductivity, modeling, implicit method, SIMPLE method, energy release, computing server, construct, supercomputer.
 ADAPTIVE ROUTING SYSTEM FOR THE DOMESTIC INTERCONNECT SMPO10G V. G. Basalov, V. M. Vyalukhin VANT. Ser.: Mat. Mod. Fiz. Proc. 2012. No 3. P. 6470.
The article reports the outcome of an effort on the development of adaptive routing algorithms for the domestic interconnect SMPO10G. The choice of local adaptive routing as an optimal solution for SMPO10G is substantiated. The mechanism of communication environment initialization and the message routing algorithm developed for are described. Details of the algorithm for choosing the optimal outlet switch port during message passing are presented. The mechanism of broadcast exchange for SMPO10G is described. Key words: multiprocessor computer, interconnect, SMPO10G, topology of communication environment, local adaptive routing, broadcasting mechanism.
 REGULAR EXPRESSIONS IN NUCLEAR TRANSMUTATION SIMULATIONS A. R. Belozerova VANT. Ser.: Mat. Mod. Fiz. Proc. 2012. No 3. P. 7178.
Mathematical modeling of neutron radiationinduced nuclear transformation (transmutation) processes in matter allows us to study the effects of radiation on nuclear physics properties and radiation properties of reactor materials. As a user tool we used "A Metrologist’s Universal Program” (MUP) under OS Windows 9x/2000/XP/NT. This version of the software offers a graphic interface for databases and has an extended menu for nuclear transmutation simulations of structural materials, radiationinduced activity in structural materials using neutronics properties, chemical composition of materials and branched schemes of nuclide transformations, and for neutron spectrum recovery from experimental data. Regular expressions are widely used in nuclear transmutation simulations and in processing the texts with simulations results. Key words: regular expressions, regular language, nuclear transmutation, ENDF/B6 format, evaluated nuclear data library.
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