scholarly journals Parallel algorithms for solving diffusion-convection problems on a multiprocessor computer system using hybrid MPI / OpenMP technology

2021 ◽  
Vol 2131 (2) ◽  
pp. 022008
Author(s):  
A Atayan ◽  
V Dolgov
Keyword(s):  
Mathematical Models ◽  
High Performance ◽  
Multiprocessor System ◽  
Computational Domain ◽  
Advective Transport ◽  
Multiprocessor Computer ◽  
Coastal Systems ◽  
Spreading Dynamics ◽  
Efficiency Comparison ◽  
Diffusion Convection

Abstract The paper deals with the mathematical models, algorithms and software for mathematical modeling of coastal systems’ water pollution spreading dynamics under various unfavorable phenomena of natural and artificial genesis, developed for high-performance cluster systems. Methods for partitioning the computational domain for solving diffusion-convection problems have been developed, which allow for efficient parallelization of a computationally complex modeling problem, taking into account the architecture of the multiprocessor system used. The developed mathematical models are based on high-precision models of hydrophysics and hydrobiology and take into account the peculiarities of water systems in the south of the Rostov region, as well as factors of hydrobiological dynamics such as microturbulent diffusion and advective transport in various directions, mechanisms of primary and secondary pollution of coastal systems, taking into account currents. The paper presents algorithms for solving a simulated problem based on MPI parallelization technology, as well as based on mixed MPI + OpenMP technology. Numerical experiments have been carried out and the two technologies efficiency comparison has been made in the conditions of computing cluster used.

A high performance scalable fuzzy based modified Asymmetric Heterogene Multiprocessor System on Chip (AHt-MPSOC) reconfigurable architecture

2021 ◽  
pp. 1-12
Author(s):  
Arun Prasath Raveendran ◽  
Jafar A. Alzubi ◽  
Ramesh Sekaran ◽  
Manikandan Ramachandran
Keyword(s):  
High Performance ◽  
Standard Technique ◽  
System On Chip ◽  
Mixed Integer ◽  
Multiprocessor System ◽  
Compound System ◽  
Available Bandwidth ◽  
Mip Model ◽  
Fpga Chip ◽  
On Chip

This Ensuing generation of FPGA circuit tolerates the combination of lot of hard and soft cores as well as devoted accelerators on a chip. The Heterogene Multi-Processor System-on-Chip (Ht-MPSoC) architecture accomplishes the requirement of modern applications. A compound System on Chip (SoC) system designed for single FPGA chip, and that considered for the performance/power consumption ratio. In the existing method, a FPGA based Mixed Integer Programming (MIP) model used to define the Ht-MPSoC configuration by taking into consideration the sharing hardware accelerator between the cores. However, here, the sharing method differs from one processor to another based on FPGA architecture. Hence, high number of hardware resources on a single FPGA chip with low latency and power targeted. For this reason, a fuzzy based MIP and Graph theory based Traffic Estimator (GTE) are proposed system used to define New asymmetric multiprocessor heterogene framework on microprocessor (AHt-MPSoC) architecture. The bandwidths, energy consumption, wait and transmission range are better accomplished in this suggested technique than the standard technique and it is also implemented with a multi-task framework. The new Fuzzy control-based AHt-MPSoC analysis proves significant improvement of 14.7 percent in available bandwidth and 89.8 percent of energy minimized to various traffic scenarios as compared to conventional method.

scholarly journals Models and Algorithms of Adaptive Animal Flow Control in Rotary Milking Parlors

2019 ◽  
Vol 67 (6) ◽  
pp. 1465-1484
Author(s):  
Vladimir V. Kirsanov ◽  
Andrey Y. Izmaylov ◽  
Yakov P. Lobachevsky ◽  
Oksana A. Tareeva ◽  
Sergey N. Strebulyaev ◽  
...  
Keyword(s):  
Mathematical Models ◽  
High Performance ◽  
Dairy Farm ◽  
Computing System ◽  
Scientific Basis ◽  
Idle Time ◽  
Functional Connection ◽  
Operating Modes ◽  
Nizhny Novgorod Region ◽  
Physiological Characters

The study addresses the influence of milking duration of individual cows on the performance of conveyor-like rotary milking parlors and seeks to optimize their operation parameters and operating modes. The observational experiment was conducted in the Zhdanovsky Farm in Nizhny Novgorod Region, Russia. The dairy farm had a herd of 600 cows, divided into 10 groups by physiological characters and milk yield, and operated a 36 point milking parlor. Distribution of milking time of individual cows was studied using statistical analysis methods. The cyclogram of parlor operation and the functional connection of main parameters were analyzed using Maple analytical computing system, including its standard libraries and functions. The trends in idle time, which occurs due to undermilking of animals in one turn of the parlor, were studied. The idle time can result in overestimation of the number of stalls or decrease in the nameplate performance of the milking parlor by 30–40% from 120 to 93 cows per hour. Mathematical models, taking into account the influence of the milking time of individual animals (2 to 17 minutes) on the parameters of parlor operation, were developed. The algorithms of adaptive control over the rotational speed were proposed to minimize idle time in parlor operation and maintain the nameplate performance. The mathematical models, control algorithms and developed software can serves as a scientific basis for new designs of high-performance rotary milking parlors.

Direct Numerical Simulations of a Transonic Tip Flow With Free-Stream Disturbances

2013 ◽  
Author(s):  
Andrew P. S. Wheeler ◽  
Richard D. Sandberg
Keyword(s):  
Heat Transfer ◽  
High Performance ◽  
Free Stream ◽  
Separation Bubble ◽  
Cross Flow ◽  
Turbulence Models ◽  
Navier Stokes ◽  
Computational Domain ◽  
Free Stream Turbulence ◽  
Gap Height

In this paper we use direct numerical simulation to investigate the unsteady flow over a model turbine blade-tip at engine scale Reynolds and Mach numbers. The DNS is performed with a new in-house multi-block structured compressible Navier-Stokes solver purposely developed for exploiting high-performance computing systems. The particular case of a transonic tip flow is studied since previous work has suggested compressibility has an important influence on the turbulent nature of the separation bubble at the inlet to the gap and subsequent flow reattachment. The effects of free-stream turbulence, cross-flow and pressure-side boundary-layer on the tip flow aerodynamics and heat transfer are investigated. For ‘clean’ in-flow cases we find that even at engine scale Reynolds numbers the tip flow is intermittent in nature (neither laminar nor fully turbulent). The breakdown to turbulence occurs through the development of spanwise modes with wavelengths around 25% of the gap height. Cross-flows of 25% of the streamwise gap exit velocity are found to increase the stability of the tip flow, and to significantly reduce the turbulence production in the separation bubble. This is predicted through in-house linear stability analysis, and confirmed by the DNS. For the case when the inlet flow has free-stream turbulence, viscous dissipation and the rapid acceleration of the flow at the inlet to the tip-gap causes significant distortion of the vorticity field and reductions of turbulence intensity as the flow enters the tip gap. This means that only very high turbulence levels at the inlet to the computational domain significantly affect the tip heat transfer. The DNS results are compared with RANS predictions using the Spalart-Allmaras and k–ω SST turbulence models. The RANS and DNS predictions give similar qualitative features for the tip flow, but the size and shape of the inlet separation bubble and shock positions differ noticeably. The RANS predictions are particularly insensitive to free-stream turbulence.

Two-Degree-of-Freedom Control of an Ionic Polymer-Metal Composite Actuator

2010 ◽  
Vol 670 ◽  
pp. 369-378 ◽  
Author(s):  
Minoru Sasaki ◽  
Yusuke Onouchi ◽  
Hirohisa Tamagawa ◽  
Satoshi Ito
Keyword(s):  
Transfer Function ◽  
Mathematical Models ◽  
High Performance ◽  
Input Voltage ◽  
Degree Of Freedom ◽  
Metal Composite ◽  
Ionic Polymer Metal Composites ◽  
Ionic Polymer ◽  
Polymer Metal ◽  
Two Degree Of Freedom

Mathematical models predicting the behaviour of IMPCs (Ionic Polymer-Metal Composites ) were built and their validity was verified computationally as well as experimentally. A transfer function associating the applied input voltage with the IPMC tip displacement was derived based on results obtained by vibration analysis. Employing the derived transfer function, three mathematical models, based on feed forward, feedback and two-degree-of-freedom models, were formulated. Computational and experimental verification of these models revealed that the feedback and two-degree-of-freedom models were capable of high performance in controlling the bending of an IPMC.

scholarly journals WAVE PRESSURE DISTRIBUTIONS ON A U-OWC BREAKWATER: EXPERIMENTAL DATA VS CFD MODEL

2018 ◽  
pp. 15
Author(s):  
Pasquale G. Fabio Filianoti ◽  
Luana Gurnari
Keyword(s):  
Pressure Distribution ◽  
High Performance ◽  
Ideal Gas ◽  
Navier Stokes ◽  
Eastern Coast ◽  
Computational Domain ◽  
Ansys Fluent ◽  
Wave Energy Converters ◽  
Vof Model ◽  
Line Force

U-OWCs are Wave Energy Converters belong in to the family of Oscillating Water Column. The interaction between waves and a U-OWC breakwater produces an unknown pressure distribution on the breakwater wall, due to the motion inside the plant. In order to evaluate the force acting on a U-OWC breakwater produced by regular waves, we carried out an experiment in a 2D numerical flume. The computational domain is equipped by a piston-type wavemaker, in the left extremity side and a U-OWC breakwater on the opposite side. The water-air interaction is taken into account by means of the Volume Of Fluid (VOF) model implemented in the commercial CFD code Ansys Fluent. Both air and water flow fields are assumed to be unsteady and are computed by solving the Reynolds-Averaged Navier-Stokes (RANS) equations. In the numerical model, air is considered as an ideal gas, in order to take into account the compressibility inside the plenum chamber. Results were compared with a theoretical model on a traditional vertical breakwater and experimental results obtained through an experiment directly at sea, off the beach of Reggio Calabria, in the eastern coast of the Straits of Messina (Southern Italy). As observed in the physical experiment at sea, the pressure distribution are strongly influenced by the absorption of the plant. Indeed, in case of high performance of the U-OWC, we found a deformation of the pressure distribution in respect to the theoretical one, especially near the outer opening of the plant. This deformation produces a lower in line force on the structure.

A Real-Time Tsunami Inundation Forecast System Using Vector Supercomputer SX-ACE

2018 ◽  
Vol 13 (2) ◽  
pp. 234-244 ◽  
Author(s):  
Akihiro Musa ◽  
Takashi Abe ◽  
Takuya Inoue ◽  
Hiroaki Hokari ◽  
Yoichi Murashima ◽  
...  
Keyword(s):  
Real Time ◽  
Local Governments ◽  
High Performance ◽  
Polygonal Domain ◽  
Computational Domain ◽  
Xeon Phi ◽  
Forecast System ◽  
Tsunami Inundation ◽  
City Regions ◽  
Efficient Vector

Tsunami disasters can cause serious casualties and damage to social infrastructures. An early understanding of disaster states is required in order to advise evacuations and plan rescues and recoveries. We have developed a real-time tsunami inundation forecast system using a vector supercomputer SX-ACE. The system can complete a tsunami inundation and damage estimation for coastal city regions at the resolution of a 10 m grid size in under 20 minutes, and distribute tsunami inundation and infrastructure damage information to local governments in Japan. We also develop a new configuration for the computational domain, which is changed from rectangles to polygons and called a polygonal domain, in order to effectively simulate in the entire coast of Japan. Meanwhile, new supercomputers have been developed, and their peak performances have increased year by year. In 2016, a new Xeon Phi processor calledKnights Landingwas released for high-performance computing. In this paper, we present an overview of our real-time tsunami inundation forecast system and the polygonal domain, which can decrease the amount of computation in a simulation, and then discuss its performance on a vector supercomputer SX-ACE and a supercomputer system based on Intel Xeon Phi. We also clarify that the real-time tsunami inundation forecast system requires the efficient vector processing of a supercomputer with high-performance cores.

scholarly journals Mathematical models and methods of numerical investigation of processes which accompany aircraft icing

2021 ◽  
Vol 33 (5) ◽  
pp. 237-248
Author(s):  
Ivan Alekseevich Amelyushkin ◽  
Maksim Aleksandrovich Kudrov ◽  
Alexey Olegovich Morozov ◽  
Andrey Sergeevich Shcheglov
Keyword(s):  
Numerical Modeling ◽  
Mathematical Models ◽  
High Performance ◽  
Practical Importance ◽  
Particle Dynamics ◽  
Software Systems ◽  
Aircraft Icing ◽  
Properties Of Coatings ◽  
Practical Applications ◽  
Physical And Mathematical Models

The study of aircraft icing modes, in which it is necessary to take into account the effect of droplet crushing, is of great interest in calculating the icing of aircraft, optimizing the hydrophobic and anti-icing properties of coatings, and is relevant in a number of other practical applications. Of great practical importance is the development of high-performance methods for calculating the interaction of aerosol flows with a solid. This work is devoted to the development of a model of particle dynamics, as well as a model of fragmentation of supercooled droplets of an aerosol flow during its interaction with the surface of a streamlined body. Developed physical and mathematical models can be used in software systems for numerical modeling of aircraft icing.

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