Reynolds-Averaged Navier-Stokes Simulations for High-Speed Wigley Hull in Deep and Shallow Water

2007 ◽  
Vol 51 (03) ◽  
pp. 187-203
Author(s):  
Nobuaki Sakamoto ◽  
Robert Vance Wilson ◽  
Frederick Stern

Reynolds-averaged Navier-Stokes simulations and verification and validation studies for a high-speed Wigley hull in deep and shallow water are presented using CFD-SHIP-IOWA Version 4.00, which is a general-purpose ship hydrodynamics computational fluid dynamics code: single-phase level set free surface and k-w turbulence modeling; higher-order conservative discretization, embedded overset grids, advanced iterative solvers, and implicit coupling flow field and predicted motions numerical methods; and high-performance computing for message-passing interface (MPI)-based domain decomposition. The results are presented for low to high speed and deep to shallow water. The investigation is exploratory in nature using an idealized geometry and relatively coarse grids. Based on the verification and validation results, modifications for increased grid resolution at the bow for high speed and improved grid orthogonality for shallow water are made to obtain better solutions. The flow physics observations provide both integral and differential views of the highspeed and shallow-water flow fields, including resistance, pressure variation, wave pattern, boundary layer, and vortices.

2011 ◽  
Vol 4 (1) ◽  
pp. 547-573
Author(s):  
T. Langkamp

Abstract. The Weather Research and Forecasting system version 3 (WRFv3) is an open source and state of the art numerical regional climate model used in climate related sciences. Over the years the model has been successfully optimized on a wide variety of clustered compute nodes connected with high speed interconnects. This is currently the most used hardware architecture for high-performance computing. As such, understanding WRFs dependency on the various hardware elements like the CPU, its interconnects, and the software is crucial for saving computing time. This is important because computing time in general is rare, resource intensive, and hence very expensive. This paper evaluates the influence of different compilers on WRFs performance, which was found to differ up to 26%. The paper also evaluates the performance of different message passing interface library versions, a software which is needed for multi CPU runs, and of different WRF versions. Both showed no significant influence on the performance for this test case on the used High Performance Cluster (HPC) hardware. Some emphasis is also laid on the applied non-standard method of performance measuring, which was required because of performance fluctuations between identical runs on the used HPC. Those are caused by contention for network resources, a phenomenon examined for many HPCs.


2011 ◽  
Vol 4 (3) ◽  
pp. 611-623 ◽  
Author(s):  
T. Langkamp ◽  
J. Böhner

Abstract. The Weather Research and Forecasting system version 3 (WRFv3) is an open source and state of the art numerical Regional Climate Model used in climate related sciences. These years the model has been successfully optimized on a wide variety of clustered compute nodes connected with high speed interconnects. This is currently the most used hardware architecture for high-performance computing (Shainer et al., 2009). As such, understanding the influence of hardware like the CPU, its interconnects, or the software on WRFs performance is crucial for saving computing time. This is important because computing time in general is rare, resource intensive, and hence very expensive. This paper evaluates the influence of different compilers on WRFs performance, which was found to differ up to 26 %. The paper also evaluates the performance of different Message Passing Interface library versions, a software which is needed for multi CPU runs, and of different WRF versions. Both showed no significant influence on the performance for this test case on the used High Performance Cluster (HPC) hardware. Emphasis is also laid on the applied non-standard method of performance measuring, which was required because of performance fluctuations between identical runs on the used HPC. Those are caused by contention for network resources, a phenomenon examined for many HPCs (Wright et al., 2009).


2020 ◽  
Vol 15 ◽  
Author(s):  
Weiwen Zhang ◽  
Long Wang ◽  
Theint Theint Aye ◽  
Juniarto Samsudin ◽  
Yongqing Zhu

Background: Genotype imputation as a service is developed to enable researchers to estimate genotypes on haplotyped data without performing whole genome sequencing. However, genotype imputation is computation intensive and thus it remains a challenge to satisfy the high performance requirement of genome wide association study (GWAS). Objective: In this paper, we propose a high performance computing solution for genotype imputation on supercomputers to enhance its execution performance. Method: We design and implement a multi-level parallelization that includes job level, process level and thread level parallelization, enabled by job scheduling management, message passing interface (MPI) and OpenMP, respectively. It involves job distribution, chunk partition and execution, parallelized iteration for imputation and data concatenation. Due to the design of multi-level parallelization, we can exploit the multi-machine/multi-core architecture to improve the performance of genotype imputation. Results: Experiment results show that our proposed method can outperform the Hadoop-based implementation of genotype imputation. Moreover, we conduct the experiments on supercomputers to evaluate the performance of the proposed method. The evaluation shows that it can significantly shorten the execution time, thus improving the performance for genotype imputation. Conclusion: The proposed multi-level parallelization, when deployed as an imputation as a service, will facilitate bioinformatics researchers in Singapore to conduct genotype imputation and enhance the association study.


1996 ◽  
Vol 22 (6) ◽  
pp. 789-828 ◽  
Author(s):  
William Gropp ◽  
Ewing Lusk ◽  
Nathan Doss ◽  
Anthony Skjellum

Author(s):  
Amin Najafi ◽  
Mohammad Saeed Seif

Determination of high-speed crafts’ hydrodynamic coefficients will help to analyze the dynamics of these kinds of vessels and the factors affecting their dynamic stabilities. Also, it can be useful and effective in controlling the vessel instabilities. The main purpose of this study is to determine the coefficients of longitudinal motions of a planing catamaran with and without a hydrofoil using Reynolds-averaged Navier–Stokes method to evaluate the foil effects on them. Determination of hydrodynamic coefficients by experimental approach is costly and requires meticulous laboratory equipment; therefore, utilizing the numerical methods and developing a virtual laboratory seem highly efficient. In this study, the numerical results for hydrodynamic coefficients of a high-speed craft are verified against Troesch’s experimental results. In the following, after determination of hydrodynamic coefficients of a planing catamaran with and without foil, the foil effects on its hydrodynamic coefficients are evaluated. The results indicate that most of the coefficients are frequency-independent especially at high frequencies.


2013 ◽  
Vol 718-720 ◽  
pp. 1645-1650
Author(s):  
Gen Yin Cheng ◽  
Sheng Chen Yu ◽  
Zhi Yong Wei ◽  
Shao Jie Chen ◽  
You Cheng

Commonly used commercial simulation software SYSNOISE and ANSYS is run on a single machine (can not directly run on parallel machine) when use the finite element and boundary element to simulate muffler effect, and it will take more than ten days, sometimes even twenty days to work out an exact solution as the large amount of numerical simulation. Use a high performance parallel machine which was built by 32 commercial computers and transform the finite element and boundary element simulation software into a program that can running under the MPI (message passing interface) parallel environment in order to reduce the cost of numerical simulation. The relevant data worked out from the simulation experiment demonstrate that the result effect of the numerical simulation is well. And the computing speed of the high performance parallel machine is 25 ~ 30 times a microcomputer.


Author(s):  
Alan Gray ◽  
Kevin Stratford

Leading high performance computing systems achieve their status through use of highly parallel devices such as NVIDIA graphics processing units or Intel Xeon Phi many-core CPUs. The concept of performance portability across such architectures, as well as traditional CPUs, is vital for the application programmer. In this paper we describe targetDP, a lightweight abstraction layer which allows grid-based applications to target data parallel hardware in a platform agnostic manner. We demonstrate the effectiveness of our pragmatic approach by presenting performance results for a complex fluid application (with which the model was co-designed), plus separate lattice quantum chromodynamics particle physics code. For each application, a single source code base is seen to achieve portable performance, as assessed within the context of the Roofline model. TargetDP can be combined with Message Passing Interface (MPI) to allow use on systems containing multiple nodes: we demonstrate this through provision of scaling results on traditional and graphics processing unit-accelerated large scale supercomputers.


2021 ◽  
Author(s):  
Jiecheng Zhang ◽  
George Moridis ◽  
Thomas Blasingame

Abstract The Reservoir GeoMechanics Simulator (RGMS), a geomechanics simulator based on the finite element method and parallelized using the Message Passing Interface (MPI), is developed in this work to model the stresses and deformations in subsurface systems. RGMS can be used stand-alone, or coupled with flow and transport models. pT+H V1.5, a parallel MPI-based version of the serial T+H V1.5 code that describes mass and heat flow in hydrate-bearing porous media, is also developed. Using the fixed-stress split iterative scheme, RGMS is coupled with the pT+H V1.5 to investigate the geomechanical responses associated with gas production from hydrate accumulations. The code development and testing process involve evaluation of the parallelization and of the coupling method, as well as verification and validation of the results. The parallel performance of the codes is tested on the Ada Linux cluster of the Texas A&M High Performance Research Computing using up to 512 processors, and on a Mac Pro computer with 12 processors. The investigated problems are: Group 1: Geomechanical problems solved by RGMS in 2D Cartesian and cylindrical domains and a 3D problem, involving 4x106 and 3.375 x106 elements, respectively; Group 2: Realistic problems of gas production from hydrates using pT+H V1.5 in 2D and 3D systems with 2.45x105 and 3.6 x106 elements, respectively; Group 3: The 3D problem in Group 2 solved with the coupled RGMS-pT+H V1.5 simulator, fully accounting for geomechanics. Two domain partitioning options are investigated on the Ada Linux cluster and the Mac Pro, and the code parallel performance is monitored. On the Ada Linux cluster using 512 processors, the simulation speedups (a) of RGMS are 218.89, 188.13, and 284.70 in the Group 1 problems, (b) of pT+H V1.5 are 174.25 and 341.67 in the Group 2 cases, and (c) of the coupled simulators is 331.80 in Group 3. The results produced in this work show the necessity of using full geomechanics simulators in marine hydrate-related studies because of the associated pronounced geomechanical effects on production and displacements and (b) the effectiveness of the parallel simulators developed in this study, which can be the only realistic option in these complex simulations of large multi-dimensional domains.


Author(s):  
Indar Sugiarto ◽  
Doddy Prayogo ◽  
Henry Palit ◽  
Felix Pasila ◽  
Resmana Lim ◽  
...  

This paper describes a prototype of a computing platform dedicated to artificial intelligence explorations. The platform, dubbed as PakCarik, is essentially a high throughput computing platform with GPU (graphics processing units) acceleration. PakCarik is an Indonesian acronym for Platform Komputasi Cerdas Ramah Industri Kreatif, which can be translated as “Creative Industry friendly Intelligence Computing Platform”. This platform aims to provide complete development and production environment for AI-based projects, especially to those that rely on machine learning and multiobjective optimization paradigms. The method for constructing PakCarik was based on a computer hardware assembling technique that uses commercial off-the-shelf hardware and was tested on several AI-related application scenarios. The testing methods in this experiment include: high-performance lapack (HPL) benchmarking, message passing interface (MPI) benchmarking, and TensorFlow (TF) benchmarking. From the experiment, the authors can observe that PakCarik's performance is quite similar to the commonly used cloud computing services such as Google Compute Engine and Amazon EC2, even though falls a bit behind the dedicated AI platform such as Nvidia DGX-1 used in the benchmarking experiment. Its maximum computing performance was measured at 326 Gflops. The authors conclude that PakCarik is ready to be deployed in real-world applications and it can be made even more powerful by adding more GPU cards in it.


Author(s):  
Vladimir Stegailov ◽  
Ekaterina Dlinnova ◽  
Timur Ismagilov ◽  
Mikhail Khalilov ◽  
Nikolay Kondratyuk ◽  
...  

In this article, we describe the Desmos supercomputer that consists of 32 hybrid nodes connected by a low-latency high-bandwidth Angara interconnect with torus topology. This supercomputer is aimed at cost-effective classical molecular dynamics calculations. Desmos serves as a test bed for the Angara interconnect that supports 3-D and 4-D torus network topologies and verifies its ability to unite massively parallel programming systems speeding-up effectively message-passing interface (MPI)-based applications. We describe the Angara interconnect presenting typical MPI benchmarks. Desmos benchmarks results for GROMACS, LAMMPS, VASP and CP2K are compared with the data for other high-performance computing (HPC) systems. Also, we consider the job scheduling statistics for several months of Desmos deployment.


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