National Combustion Code - Parallel implementation and performance

Quealy, Angela; Ryder, R. C.; Norris, Andrew T.; Liu, N.-S.

doi:10.2514/6.2000-336

Cited by 13 publications

(5 citation statements)

References 3 publications

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“…The National Combustion Code (NCC) is an unstructuredgrid CFD code that serves as a platform for developing new physical models for turbulence, chemistry, spray and turbulence-chemistry and turbulence-spray interactions [16]. The test case for this study simulates a complex fuel injector geometry known as the NASA C4 hydrogen injector.…”

Section: A Kernel Benchmarks and Applicationsmentioning

confidence: 99%

Performance impact of resource contention in multicore systems

Hood

Jin²,

Mehrotra³

et al. 2010

2010 IEEE International Symposium on Parallel &Amp; Distributed Processing (IPDPS)

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Resource sharing in commodity multicore processors can have a significant impact on the performance of production applications. In this paper we use a differential performance analysis methodology to quantify the costs of contention for resources in the memory hierarchy of several multicore processors used in high-end computers. In particular, by comparing runs that bind MPI processes to cores in different patterns, we can isolate the effects of resource sharing. We use this methodology to measure how such sharing affects the performance of four applications of interest to NASA-OVERFLOW, MITgcm, Cart3D, and NCC. We also use a subset of the HPCC benchmarks and hardware counter data to help interpret and validate our findings. We conduct our study on high-end computing platforms that use four different quadcore microprocessors-Intel Clovertown, Intel Harpertown, AMD Barcelona, and Intel Nehalem-EP. The results help further our understanding of the requirements these codes place on their production environments and also of each computer's ability to deliver performance.

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Section: A Kernel Benchmarks and Applicationsmentioning

confidence: 99%

Performance impact of resource contention in multicore systems

Hood

Jin²,

Mehrotra³

et al. 2010

2010 IEEE International Symposium on Parallel &Amp; Distributed Processing (IPDPS)

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“…The National Combustion Code (NCC) is a state of the art Computational Fluiid Dynamics (CFD) program specifically designed for combustion processes 1 . The code employs an unstructured grid, massively parallel computing 2,3 , a dynamic wall function with the effect of adverse pressure gradient 4 , a low Reynolds number wall treatment 5 , a cubic non-linear k-epsilon turbulence model 6 , a lagrangian liquid phase spray model 7 , and stiff laminar chemistry integration. Recently, viscous low-speed preconditioning 8 has been added to improve the low-speed convergence of the NCC in viscous regions and the ability to handle multiple sets of periodic boundary conditions has also been added.…”

Section: Introductionmentioning

confidence: 99%

An Upwind Solver for the National Combustion Code

Sockol

2011

49th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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An upwind solver is presented for the unstructured grid National Combustion Code (NCC). The compressible Navier-Stokes equations with time-derivative preconditioning and preconditioned fluxdifference splitting of the inviscid terms are used. First order derivatives are computed on cell faces and used to evaluate the shear stresses and heat fluxes. A new flux limiter uses these same first order derivatives in the evaluation of left and right states used in the flux-difference splitting. The k-epsilon turbulence equations are solved with the same second-order method. The new solver has been installed in a recent version of NCC and the resulting code has been tested successfully in 2D on two laminar cases with known solutions and one turbulent case with experimental data.

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“…The input dataset is 1.6 GB in size, and the solution file is 2 GB. NCC, the National Combustion Code, is an unstructuredgrid Navier-Stokes CFD application used to develop new physical models for turbulence, chemistry, spray, and turbulence-chemistry, as well as turbulence-spray interactions [16]. It employs a cell-centered finite-volume spatial discretization and pseudo-time preconditioning.…”

Section: B Westmere-ep Performance Counter Eventsmentioning

confidence: 99%

The impact of hyper-threading on processor resource utilization in production applications

Saini

Jin

Hood

et al. 2011

2011 18th International Conference on High Performance Computing

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Abstract-Intel provides Hyper-Threading (HT) in processors based on its Pentium and Nehalem micro-architecture such as the Westmere-EP. HT enables two threads to execute on each core in order to hide latencies related to data access. These two threads can execute simultaneously, filling unused stages in the functional unit pipelines. To aid better understanding of HTrelated issues, we collect Performance Monitoring Unit (PMU) data (instructions retired; unhalted core cycles; L2 and L3 cache hits and misses; vector and scalar floating-point operations, etc.). We then use the PMU data to calculate a new metric of efficiency in order to quantify processor resource utilization and make comparisons of that utilization between single-threading (ST) and HT modes. We also study performance gain using unhalted core cycles, code efficiency of using vector units of the processor, and the impact of HT mode on various shared resources like L2 and L3 cache. Results using four full-scale, production-quality scientific applications from computational fluid dynamics (CFD) used by NASA scientists indicate that HT generally improves processor resource utilization efficiency, but does not necessarily translate into overall application performance gain.

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National Combustion Code - Parallel implementation and performance

Abstract: 17.SECURITY CLASSI FICATION

Cited by 13 publications

References 3 publications

Performance impact of resource contention in multicore systems

Performance impact of resource contention in multicore systems

An Upwind Solver for the National Combustion Code

The impact of hyper-threading on processor resource utilization in production applications

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