January 2013 - Allocations-admins - mailman3.cels.anl.gov

[LCRC Accounts] Project Allocation Request
by accounts＠lcrc.anl.gov 28 Jan '13

28 Jan '13

Hello, A change in allocation has been requested: Requester: paul (Mark Paul) Project: Chaos Title: Spatiotemporal chaos and turbulence in fluids Description: This is a continuing project with this year's allocation request building upon last year's progress. All of our calculations use spectral element methods to explore the spatiotemporal chaos and turbulence of fluid systems. The code nek5000 has previously demonstrated scalability and efficiency for the specific problems that we are interested in. We continue to make significant progress on the numerical simulation of Rayleigh-Benard convection for experimentally realistic conditions. Rayleigh-Benard convection is the buoyancy induced convection that occurs when a fluid layer is heated uniformly from below. We are most interested in cases where the fluid dynamics of the convection layer is chaotic or turbulent. Specifically, the code integrates the three-dimensional time-dependent Boussinesq equations, any associated reaction-diffusion-advection equations for the transport of scalar quantities of interest, and the linearized tangent-space equations for computing Lyapunov diagnostics. The code is geometrically flexible and can handle a number of experimentally appropriate boundary conditions. The Lyapunov diagnostics we can compute include the spectrum of Lyapunov exponents and vectors that can be used to provide fundamental insights into the complex dynamics that include the fractal dimension and the location of fast growing perturbations. In this allocation we propose to continue exploring the following problems. 1) Transport in chaotic flow fields In this project we are interested in exploring the transport dynamics of a scalar species when the underlying fluid dynamics are spatiotemporally chaotic. There are a number of situations in which this is important and we will explore two in particular. First, is the combustion of premixed gases in a chaotic flow field. Second, is the motion of swimming microorganisms in a fluid layer. Both of these situations can be described by an additional reaction-diffusion-advection equation that is solved simultaneously with the Boussinesq equations that describe the fluid motion of Rayleigh-Benard convection. The nek5000 code already has this apability and our proposed work does not involve significant additional code development. Over the past year we have explored a number of validation cases to ensure the accuracy of the code for the parameter space that we are interested in. We have computed the transport of a passive scalar quantity in a large shallow fluid layer that is undergoing spiral defect chaos. This allowed us to connect our work with previous calculations in the literature (Chiam et al, Physical Review E, 036205, 2005). This has also provided a baseline computation of the passive transport of a scalar quantity. This baseline computation allows for an important for comparison with the cases where the scalar quantity is not passive but active which we will continue to explore in this allocation. A specific case of interest is the combustion of a scalar quantity in a chaotic flow field. We have begun these calculations and validated the basic approach. With this allocation we will explore the parameter space to quantify the transport of an active scalar. In particular we are interested i n cases of small Lewis and large Damkohler numbers that are most closely related to experiment. 2) Quantifying spatiotemporal chaos In this effort we will perform large scale numerical simulations of chaotic fluid convection for the precise conditions of experiment. We will explore large cylindrical domains with aspect ratios of 30 and larger for very long times (several horizontal diffusion times). We are particularly interested in using and developing diagnostics that shed physical insight upon fundamental features of the underlying high-dimensional chaos. We will use our current capability to compute the Lyapunov exponents, Lyapunov vectors, and the fractal dimension (all using the Gram-Schmidt approach) for a range of conditions of current experimental interest in the convection community. One aspect we will focus upon is using the temporal and spatial averages of the leading order Lyapunov vector to quantify regions and dynamics of interest. We are interested in searching for a connection between these Lyapunov based diagnostics, which can only be computed and are not accessible to experiment, with quantities and diagnostics that can be measured in experiment. We will also develop and explore new diagnostics such as covariant Lyapunov vectors to quantify the spatial disorder in the patterns. The covariant Lyapunov vectors are much more difficult to calculate than the Gram-Schmidt based Lyapunov vectors but have the benefit of providing all of the directions of perturbation growth in the high dimensional phase space (called Oseledec's splitting). The covariant Lyapunov vectors have not been calculated for an experimentally accessible fluid system and have the potential to provide new and important insights into the regions and directions that contribute most to the chaos. In order to connect with experiment we are also going to explore the use of realistic boundary conditions such as walls of finite thermal conductivity and varying fluid properties. 3) Turbulent thermal convection. We would like to continue our three-dimensional numerical simulations of fully turbulent Rayleigh-Benard convection cells for higher Rayleigh numbers (10E10) and lower Prandtl number (0.02-0.7). Simulations have never been performed at such high Rayleigh numbers, system size and Prandtl number. This is exactly the region where there is disagreement between theory and experiments, and there is evidence of a trend towards disagreement by our simulation results at lower Rayleigh number. By going to higher Rayleigh number, we will be able to resolve the disagreements and develop a fuller understanding of turbulence. Many experiments are currently being performed in the proposed regime (and even higher Rayleigh number), but this system is not well understood theoretically. Thermal plumes are present in turbulent convection as a means of heat transport. In addition, a large-scale circulation (LSC) has been found, which sweeps the thermal plumes along like leaves in a wind. This LSC is not steady and also undergoes chaotic, abrupt reversals. Visualizations are extremely difficult in experiments, so numerical simulations are essential for bridging the gap between experiment and theory. Heat transport measurements can also be determined from these simulations and compared to experiments and theoretical predictions. Thin thermal and viscous boundary layers are present, and we can perform a detailed analysis of these boundary layers, which are key to understanding the nature of turbulence in these cells. Finally Lyapunov exponents can be computed for these systems and a correlation is expected between the time dependence of the LSC and the time dependence of one of the Lyapunov exponents. Turbulent Rayleigh-Benard systems have application to such diverse phenomena as weather forecasting and the reversal of the earth's magnetic field. URL: More information can be found at the following URL's Janet Scheel http://faculty.oxy.edu/jscheel/research.html Mark Paul http://www.me.vt.edu/mpaul Paul Fischer http://www.mcs.anl.gov/~fischer/ Allocation request: 150,000 Transport in chaotic convection 150,000 Covariant Lyapunov vectors and exponents 150,000 Turbulent thermal convection 450,000 Total Request Current: undetermined amount Justification: N/A Requested: 120000 A specific reason has been given: Our project now has 4 numerical explorations that are in the full production phase on fusion. We have also recently completed a careful validation and verification phase that required significant effort. We are encouraged by the results we now have in hand and are excited to push forward. We would also like to point out that we had hours removed from our allocation during the first part of the year as a result of our reduced core hour usage use while validating. Given our current progress and efforts we would like to request an additional 120000 core hours. Our current allocation is nearly exhausted and we are using fusion heavily with great success. Please do not hesitate to contact me if there is any further information we can provide. Thank you, Mark Paul This needs to be approved and the final allocation amount decided upon. Thank You, The LCRC Accounts System

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[LCRC Accounts] Project Allocation Request
by accounts＠lcrc.anl.gov 27 Jan '13

27 Jan '13

Hello, A change in allocation has been requested: Requester: jiechen (Jie Chen) Project: ScalaGAUSS Title: Scalable Gaussian Process Data Analysis Description: ScalaGAUSS is a statistical software for analyzing spatialtemporal data arising from various applications (chemistry, power grids, material science) and modeled as a Gaussian process. The goal of ScalaGAUSS is to handle both gridded and scattered data at the scale of 10^9 to 10^12 points and beyond. Following the framework of a reformulation of the maximum likelihood estimation using sample average approximation, the core of the computations is to solve several linear systems with respect to the fully dense covariance matrix (having the number of rows/columns the same the data size). For gridded data, we implemented a multilevel Toeplitz linear solver and tested it with up to 1024 cores last year; see the FY2012 report. This year’s work will be built on that of the last year. In particular, we will be focusing on 1. Improving the scaling of the solver; 2. Incorporating the solver into ScalaGAUSS. The objective is to finish a working version of ScalaGAUSS that can be applied to real applications, such as for analyzing ozone data. On the other hand, for scatted data, a linear solver requires efficient matrix-vector multiplications. For this, we have developed a fast summation program for a specific covariance kernel, based on the treecode methodology. This program will be the essential building block of the linear solver. We will be investigating its performance for solving linear systems. The goal is to add to ScalaGAUSS a component that handles scattered data as efficiently as for gridded data. Current: undetermined amount Justification: Requested: 150000 A specific reason has been given: Quota has been run out for the first half of the FY. I am requesting additional allocation to continue the experiments. This needs to be approved and the final allocation amount decided upon. Thank You, The LCRC Accounts System

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[LCRC Accounts] Project Allocation Request
by accounts＠lcrc.anl.gov 26 Jan '13

26 Jan '13

Hello, A change in allocation has been requested: Requester: balaji (Pavan Balaji) Project: radix Title: Scalable Parallel System Software Description: This is a Computer Science request for 49,500 cpu-hours on Fusion for development and evaluation of a family of tools and libraries with a direct benefit to all users of high-performance computing resources. The Radix group in Argonnne's Mathematics and Computer Science division conducts research and development on facilities to better enable efficient Parallel Programming, I/O, and Scientific Understanding. The Fusion system represents an attractive milestone for our software development: projects start out on our breadboard cluster and can further explore scalability in the presence of a high speed network on Fusion before making the jump to BlueGene-scale parallelism. Radix experiments often are concerned with latency. The infiniband network on Fusion provides an excellent low-latency environment for message passing and storage management research while also providing ample bandwidth for I/O and message bandwidth testing. For FY2013 our Messaging middleware experiments include the usual MPICH2 development. We will study the continued improvement of various MPI features including scalability and memory usage, performance tuning, high-level libraries on top of MPI, fault tolerance capabilities, one-sided communication, and collective operations. This allocation will also be used for studying MPI extensions including active messages, and compiler support for MPI refactoring. We also plan for developing application-oriented libraries like ADLB, a load-balancing library. We will port the ADLB load-balancing library to Fusion and test its ability to function with multi-core nodes at intermediate scale, taking advantage of the multiple cores to replace MPI communication with local shared memory. The NWChem library will continue to improve the performance of an important scientific application that is widely used for science by Argonne researchers. Specifically, we will develop inspect-executor load-balancing techniques that will reduce network contention and improve the overall performance and scalability of an important family of methods (coupled-cluster methods). Furthermore, we will explore hybrid programming models (that is, adding threading to the existing GA/ARMCI/MPI model), particularly in the TCE module, which has been used extensively by researchers in Argonne MSD and CSE. All the aforementioned developments will be deployed on Fusion in a production fashion and made available to all users. This allocation will enable Jeff Hammond to maintain the NWChem installations on Fusion, as he has done since the machine went live. We work closely with application scientists, and develop application tools under the 'radix' allocation. For one example, the KMI project defines a high-level standardized interface for computational biology applications relying on distributed search and match semantics for biological reads. We will study efficient data management and data movement techniques to allow scaling to large number of processes. Fusion hosts two quality parallel file systems, GPFS and PVFS. The wider HPC community often asks the Radix file system researchers to compare these file systems head-to-head. Fusion provides us the opportunity to do just that. For FY 2013 our file system research extends into data storage approaches suitable for exascale. Our research into object storage protocols, including high performance access and replication, fits well on Fusion, with the large amount of local storage on compute nodes. Our Exascale storage efforts will explore scalable algorithms for use in next generation HPC storage systems. The Fusion allocation will be used to evaluate programming models, fault detection algorithms, synchronization primitives, and fault tolerance strategies for a prototype object storage system. Our NoLoss project explores how to integrate in-system storage in the I/O software stack. Under the NoLoss project, an abstraction layer for in-system storage was developed. The SCR checkpointing library was modified to store checkpoints locally using this newly developed abstraction layer. The fusion allocation will be used to explore the performance characteristics of this new approach. Hosting two parallel file systems allows us to do more than just drag-race (so to speak). The two file systems have distinct characteristics, and act differently in the broader role of the I/O software stack. On Fusion, we can utilize a single software stack (application, parallel-netcdf, ROMIO), and compare the impact of a change in the underlying file system on overall application behavior. We know from other research, for example, that the two-phase optimization in ROMIO needs to adapt to the underlying file system, and that aligning variables to file system boundaries can yield performance improvements for parallel-netcdf. In FY 2013 we are continuing research into new high level I/O libraries. We anticipate Fusion and Surveyor will be our two main test platforms. Fusion compute nodes actually look fairly attractive to active storage research. These nodes have enough disk space to store non-trivial datasets, and powerful enough processors to carry out complex computations without much impact on storage performance. Radix projects also focus on deriving insight both about application behavior as well as scientific insight. 8 core nodes make efforts like in-situ visualization, where for example an application renders a frame of a movie, ever more feasible. Even without fancy graphics accelerators, the processing power on Fusion nodes makes such analysis and visualization feasible, especially if the visualization can take advantage of multiple cores and multiple nodes. Naturally, the radix visualization tools have demonstrated scalability to Fusion sizes and beyond on Blue Gene, so making full utilization of Fusion should not be a concern. As should be evident from the variety of planned experiments, the Radix group plans to make full use of Fusion. With Argonne employees and student collaborators, we expect around 20 members in FY2013. We plan on about 0% of our jobs being single core jobs. It's crazy that you even have to ask! While Fusion may contain a modest number of compute nodes, the machine still represents an attractive platform for testing: very fast, low latency interconnect; 8 cores per node; .25 TB of storage per compute node. The testing and experiments the Radix group can carry out on Fusion ensures the tools the group develops today will remain relevant even as supercomputers grow. Quite a few radix-developed projects are part of the Fusion software stack: CPU hours for this project yield improvements and benefits not just for the radix group, but for all users of Fusion and indeed users of high-end computational resources worldwide. Current: undetermined amount Justification: Requested: 200000 A specific reason has been given: We have several ongoing projects that we are aiming for the upcoming conference deadlines. We need to get a bunch of results for these and our current allocation will not be sufficient for these tests. This needs to be approved and the final allocation amount decided upon. Thank You, The LCRC Accounts System

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Re: [allocations-admins] [LCRC Accounts] Project Allocation Request
by John Valdes 24 Jan '13

24 Jan '13

Grant 150,000 for current quarter. John On Wed, Jan 23, 2013 at 03:11:41PM -0600, accounts(a)lcrc.anl.gov wrote: > Hello, > > A change in allocation has been requested: > > Requester: kclau (Kah Chun Lau) > Project: Li_air_battery > Title: Computational studies of Li-Air battery components > Description: In the coming fiscal year (FY2013), we will complete our current on-going work and explore different systems in Li-air batteries based on experimental input from our colleagues at ANL. To complete the current ongoing study (i.e. ionic transport, ether-based solvents with different Li-salts), our experience indicates that 100, 000 hours is required. For our new study at FY2013, the computational methods will involve largely AIMD (CPMD, VASP) and DFT method (Gaussian09, VASP). For Gaussian09, the DFT calculation scales well up to 8 processors and for 4-6 nodes is the optimal number of nodes for geometry optimization for system size below 100 atoms. We will likely require about 100,000 core hours to study the stability and reaction paths of new longer ether-based (i.e. with spacer and dopants) and DMSO solvents against different Li salts in gas phase and solution phase. To extend our previous DFT study on Li2O2 (crystalline bulk, surfaces and clusters) system, mo > re extensive solid phases of Li2O2/LiO2 and Li2O/Li2O2/LiO2 hetero-interfaces (with and without impurity/dopants), together with the equation of states, mechanical, electronic and thermodynamic properties will be explored using DFT planewave VASP code. The VASP code is well-parallelized for 64-72 cores for 100-200 atoms system for a finite k-point calculation. For a single ??-point calculation with a total atom ~ 300 atoms, a parallel efficiency of ~ 60% -75% can be achieved using 256 cores. Thus to explore a moderately large systems (~ 100-200 atoms), 200 000 core-hour is needed to perform the tasks. In addition, the larger system of combined electrolyte/electrode (electrolyte/Li2O2/carbon with and without metal catalyst) (~ 400 atoms) interfaces will be computed using CPMD and VASP code. We will explore the chemical reactions (i.e. rare events) based on AIMD method. For system involves metal-catalyst (e.g. Au) that involves d-orbital electrons, the blue-moon approach based > on VASP code will be used. For a system without metal catalyst, the metadynamics approach implemented in CPMD code will be used. In order to have a reliable statistics and long enough simulation time, we will require about 400, 000 core hours to complete these computational intensive simulations. > Current: undetermined amount > Justification: For the details and evidence how to use the hours effectively, please see the project description and project report (FY2012). Further details of the scaling and the performance of the codes can be found as follows: > (1) VASP: http://cms.mpi.univie.ac.at/vasp/vasp/Performance_parallel_code_on_various_… > > (2) CPMD: http://cpmd.org/documentation > > (3) Gaussian09: http://www.gaussian.com/g_prod/g09_glance.htm > > > > Requested: 200000 > > A specific reason has been given: > Need to finish up on-going calculations for paper write-up > > This needs to be approved and the final allocation amount decided upon. > > Thank You, > The LCRC Accounts System > _______________________________________________ > allocations-admins mailing list > allocations-admins(a)lists.lcrc.anl.gov > https://lists.lcrc.anl.gov/mailman/listinfo/allocations-admins

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[LCRC Accounts] Project Allocation Request
by accounts＠lcrc.anl.gov 23 Jan '13

23 Jan '13

Hello, A change in allocation has been requested: Requester: kclau (Kah Chun Lau) Project: Li_air_battery Title: Computational studies of Li-Air battery components Description: In the coming fiscal year (FY2013), we will complete our current on-going work and explore different systems in Li-air batteries based on experimental input from our colleagues at ANL. To complete the current ongoing study (i.e. ionic transport, ether-based solvents with different Li-salts), our experience indicates that 100, 000 hours is required. For our new study at FY2013, the computational methods will involve largely AIMD (CPMD, VASP) and DFT method (Gaussian09, VASP). For Gaussian09, the DFT calculation scales well up to 8 processors and for 4-6 nodes is the optimal number of nodes for geometry optimization for system size below 100 atoms. We will likely require about 100,000 core hours to study the stability and reaction paths of new longer ether-based (i.e. with spacer and dopants) and DMSO solvents against different Li salts in gas phase and solution phase. To extend our previous DFT study on Li2O2 (crystalline bulk, surfaces and clusters) system, mo re extensive solid phases of Li2O2/LiO2 and Li2O/Li2O2/LiO2 hetero-interfaces (with and without impurity/dopants), together with the equation of states, mechanical, electronic and thermodynamic properties will be explored using DFT planewave VASP code. The VASP code is well-parallelized for 64-72 cores for 100-200 atoms system for a finite k-point calculation. For a single Γ-point calculation with a total atom ~ 300 atoms, a parallel efficiency of ~ 60% -75% can be achieved using 256 cores. Thus to explore a moderately large systems (~ 100-200 atoms), 200 000 core-hour is needed to perform the tasks. In addition, the larger system of combined electrolyte/electrode (electrolyte/Li2O2/carbon with and without metal catalyst) (~ 400 atoms) interfaces will be computed using CPMD and VASP code. We will explore the chemical reactions (i.e. rare events) based on AIMD method. For system involves metal-catalyst (e.g. Au) that involves d-orbital electrons, the blue-moon approach based on VASP code will be used. For a system without metal catalyst, the metadynamics approach implemented in CPMD code will be used. In order to have a reliable statistics and long enough simulation time, we will require about 400, 000 core hours to complete these computational intensive simulations. Current: undetermined amount Justification: For the details and evidence how to use the hours effectively, please see the project description and project report (FY2012). Further details of the scaling and the performance of the codes can be found as follows: (1) VASP: http://cms.mpi.univie.ac.at/vasp/vasp/Performance_parallel_code_on_various_… (2) CPMD: http://cpmd.org/documentation (3) Gaussian09: http://www.gaussian.com/g_prod/g09_glance.htm Requested: 200000 A specific reason has been given: Need to finish up on-going calculations for paper write-up This needs to be approved and the final allocation amount decided upon. Thank You, The LCRC Accounts System

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[LCRC Accounts] Project Request: GDI_lean_burn
by accounts＠lcrc.anl.gov 18 Jan '13

18 Jan '13

Hello, A new project on the LCRC cluster has been requested. Please forward the information on to the LCRC Allocation sub-committee. Applicant's name: Riccardo Scarcelli Applicant's institution: ANL Applicant's division: ES Project Name: GDI_lean_burn Project title: Investigation of advanced, high-efficiency, lean-burn gasoline combustion Associated funding: DOE - Office of Vehicle Technologies Other Systems: Science: This project focuses on ultra-lean burn gasoline combustion with focus on ignition system aspects and their effects on combustion behavior. This activity directly addresses the barrier of robust lean-burn and EGR-diluted combustion technology and controls, especially relevant to the growing trend of boosting and down-sizing engines as outlined in the U.S. DRIVE Advanced Combustion and Emissions Control Tech Team (ACEC) Roadmap. Project description: Specific tasks designed to mitigate this barrier include a comprehensive understanding of intake air flow, evolution of the fuel spray, ignition, combustion and emissions formation mechanisms, and their interaction with chamber/piston geometry and fuel injection strategies over a wide operating range as well as a systematic investigation of new ignition systems. 3D-CFD simulation will provide proper insight into the experimental results and offer guidance for improvements. Following the homogeneous operation, basic stratification strategies will be proposed through CFD and evaluated experimentally. Upon completion of the baseline engine assessment the focus will be shifted towards evaluation of advanced ignition systems.Improved combustion stability as well as potential extension of lean operating limits are going to be the key criteria for the assessment of advanced ignition systems. Given the different performance variables of these advanced ignition systems (ignition energy, location of ignition, multi-pulse etc.), 3D-CFD simulation will play a key role in determining engine operating parameters to fully utilize the potential of each advanced ignition system. CFD simulations will be performed with CONVERGE Project URL: Requested allocation: 210000 Q1: 0 Q2: 70000 Q3: 70000 Q4: 70000 Justification: The requester has used undetermined amount hours of their initial startup project. In addition to approving an initial amount, please specify a Category and Subcategory for this project. For a list of the current selection of approved categories, please see: https://wiki.lcrc.anl.gov/wiki/Processes/Categories Once the Allocation committee has approved the project, please go to the Project Management page to create it: https://accounts.lcrc.anl.gov/projects.php Thank You, The LCRC Accounts System

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[LCRC Accounts] Yearly Allocation Request from Dow-scaling
by accounts＠lcrc.anl.gov 15 Jan '13

15 Jan '13

Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Shashi Aithal Project Name: Dow-scaling Division: CLS Project title: Scaling studies on multiphysics flow simulations for Dow Associated funding: Other Systems: Dow internal clusters, NCSA Science: The primary goal of this project is to conduct multi-physics flow simulations using STAR-CCM+, OpenFoam and an in-house code. Project description: Two main problems will be studied in this project, namely, (1)LES study of stirred tank and (2) Gaseous jets and liquid atomization. LES study of stirred tank: The turbulent mixing inside a stirred tank reactor comprises of a number mixing scales based on the Bourne Protocol. RANS simulations do not discriminate these scales. In order to gain a better understanding the mixing patterns and their impact on polymeric reactions, de tailed turbulent structures needs to be resolved through LES in a more manageable way. Software: StarCCM+ and Openfoam Type of computation: transient, reactive flow. Planned # of cores/case: e.g. 128 cores for each case (based on known or anticipated scaling performance) probably 128 to 512 cores. Estimated core-hours per case: approx 2000 Estimated # of cases: 15 cases Project: Gaseous jets and liquid atomization - The primary droplet break-up for atomization is a very challenging problem due to its large spectrum of spatial and temporal scales. Sprays are an integral part of many applications ranging from automotive to agriculture. Without significant computing power, it is almost impossible to understand the impact of rheology and surfactants on atomization and find solutions to improve the quality of liquid sprays. This project is to investigate a number of rheology modifiers and their impact on spray behavior. Software: StarCCM+ and In-house code Type of computation: transient, multiphase, LES Planned # of cores/case: e.g. 128 to 256 cores for each case (based on known or anticipated scaling performance) probably 512 to 1024 cores. Estimated core-hours per case: probably 10000 Estimated # of cases: 10 cases Project URL: Current FY Hours Used: undetermined amount New FY Requested allocation: 130000 Q1: 0 Q2: 30000 Q3: 50000 Q4: 50000 Justification: Thank You, The LCRC Accounts System

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[LCRC Accounts] Project Allocation Request
by accounts＠lcrc.anl.gov 15 Jan '13

15 Jan '13

Hello, A change in allocation has been requested: Requester: sinclair (Donald Sinclair) Project: Lattice-QCD Title: Lattice simulations of Conformal and Walking Technicolor. Description: We perform simulations to evaluate the functional integrals of QCD-like theories formulated on a discrete space-time lattice, to enable determination of the non-perturbative aspects these theories. These include the properties of these theories at non-zero temperature, including the scales of confinement and chiral symmetry breaking, and such zero temperature properties as spectra (including the Higgs mass), decay constants and the running of the gauge coupling constant. We are particularly interested in those theories where the coupling constant evolves very slowly, since these are candidate 'Walking Technicolor' theories. Related to these are theories with an infrared fixed point (conformal field theories). Our first goal is to differentiate between these two different types of behaviour for candidate theories. We are performing simulations of QCD-like theories which are models for Walking or Conformal Technicolor. We have been studying theories which are essentially QCD but with colour-sextet rather than colour-triplet quarks. We hope to measure the running of the QCD coupling constant. For 2 or 3 flavours, 2-loop perturbation theory predicts an infrared fixed point. For 2 flavours, it is possible that a chiral condensate forms before this fixed point is reached. If so, the fixed point is avoided, the theory is confining, and chiral symmetry breaks spontaneously. However, there is a region where the coupling constant evolves very slowly. These are the properties required for a walking technicolor theory. Simulations we have performed so far at finite temperature suggest that this theory might walk. This is an ongoing program at NERSC. We are also running small-lattice simulations of the 3-flavour theory, which we expect to have conformal, rather than walking behaviour on Fusion, for comparison. If we are correct, the properties of the 2 and 3 flavour theories should look rather different. In addition to finishing these 3-flavour runs on Fusion, we plan to extend some earlier 2-flavour work on Fusion on a 24^3*8 lattice to compare with our work at NERSC on 16^3*8 lattices. These 24^3*8 runs will be of a much more limited scope than those on 16^3*8 lattices, and are needed to check that finite size effects are under control. Our sextet quark codes are based on our earlier triplet quark codes and use the RHMC simulation method. The Rational Hybrid Monte Carlo (RHMC) is a stochastic molecular dynamics algorithm. The functional integral of QCD is written as a partition function of a classical field theory evolving in a fictitious time. The determinant of the Dirac operator raised to a fractional power is calculated by introducing bosonic fields (pseudofermions), and sandwiching this Dirac operator raised to minus said fractional power between them. This fractional power of the Dirac operator is approximated to machine accuracy by a rational approximation. After defining this this theory on a discrete space-time lattice, the inversions required by the partial-fraction expansion of the rational approximation are performed using Krylov space methods, in particular a multi-shift extension of the conjugate gradient algorithm. A global Metropolis Monte-Carlo accept/reject step applied at the end of each trajectory removes discretization errors introduced by the numerical integration of these stochastic equations of motion. We parallelize the code by assigning a fixed number of adjacent lattice sites to each MPI task. Network bandwidth ultimately limits how small a chunk of the lattice can be assigned to each task. Experience with benchmarking this code on a variety of lattice sizes indicates that we should expect a performance of approximately 3 Gflops/core for a 24^3*8 lattice running on 192 cores, i.e. around 550 to 600 Gflops. In each case we have checked, this per core performance remains nearly constant as the number of cores is varied, so that maximum throughput is achieved at the largest number of cores allowed by the current implementation (in this case 192). Current: undetermined amount Justification: The per core performance for the 24^3*8 runs is approximately 3 Gflops on 192 cores. Althought we have not performed such a detailed analysis as for the 24^3*12 lattice, we expect at worst a linear speedup from the minimum number of cores (8) to the maximum number of cores (192). We note that the single node environment -- size and shape of the sublattice and communication pattern -- is identical for these 2 lattice sizes, which is why a separate performance analysis is unnecessary. This code has been running effectively on Fusion since it was released to the user community. We will be concentrating on the 2-flavour runs on 24^3*8 lattices with m=0.0025 on Fusion. Each run is expected to take approximately 60 wallclock-hours, and we are budgeting for 80 such runs. We are not providing detailed scaling analysis, since this was provided in previous years, and the code is unchanged. The main enhancement we have planned for this year is to rearrange the task to node assignments to assign a 24^2*4*2 section of the lattice to each node, rather than the default 24^2*8*1 section, by setting MPICH_RANK_REORDER_METHOD=3 and providing an appropriate MPICH_RANK_ORDER file. This will reduce the communication overhead. Any reduction of CPU time obtained by this enhancement will be used to finish our current project on a 16^3*8 lattice using 128 cores. Requested: 250000 A specific reason has been given: I have exhausted my current allocation, but the project is not yet completed. Note that my original request was for 960000, and my allocation was only 250000. This needs to be approved and the final allocation amount decided upon. Thank You, The LCRC Accounts System

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[LCRC Accounts] Project Allocation Request
by accounts＠lcrc.anl.gov 15 Jan '13

15 Jan '13

Hello, A change in allocation has been requested: Requester: sinclair (Donald Sinclair) Project: Lattice-QCD Title: Lattice simulations of Conformal and Walking Technicolor. Description: We perform simulations to evaluate the functional integrals of QCD-like theories formulated on a discrete space-time lattice, to enable determination of the non-perturbative aspects these theories. These include the properties of these theories at non-zero temperature, including the scales of confinement and chiral symmetry breaking, and such zero temperature properties as spectra (including the Higgs mass), decay constants and the running of the gauge coupling constant. We are particularly interested in those theories where the coupling constant evolves very slowly, since these are candidate 'Walking Technicolor' theories. Related to these are theories with an infrared fixed point (conformal field theories). Our first goal is to differentiate between these two different types of behaviour for candidate theories. We are performing simulations of QCD-like theories which are models for Walking or Conformal Technicolor. We have been studying theories which are essentially QCD but with colour-sextet rather than colour-triplet quarks. We hope to measure the running of the QCD coupling constant. For 2 or 3 flavours, 2-loop perturbation theory predicts an infrared fixed point. For 2 flavours, it is possible that a chiral condensate forms before this fixed point is reached. If so, the fixed point is avoided, the theory is confining, and chiral symmetry breaks spontaneously. However, there is a region where the coupling constant evolves very slowly. These are the properties required for a walking technicolor theory. Simulations we have performed so far at finite temperature suggest that this theory might walk. This is an ongoing program at NERSC. We are also running small-lattice simulations of the 3-flavour theory, which we expect to have conformal, rather than walking behaviour on Fusion, for comparison. If we are correct, the properties of the 2 and 3 flavour theories should look rather different. In addition to finishing these 3-flavour runs on Fusion, we plan to extend some earlier 2-flavour work on Fusion on a 24^3*8 lattice to compare with our work at NERSC on 16^3*8 lattices. These 24^3*8 runs will be of a much more limited scope than those on 16^3*8 lattices, and are needed to check that finite size effects are under control. Our sextet quark codes are based on our earlier triplet quark codes and use the RHMC simulation method. The Rational Hybrid Monte Carlo (RHMC) is a stochastic molecular dynamics algorithm. The functional integral of QCD is written as a partition function of a classical field theory evolving in a fictitious time. The determinant of the Dirac operator raised to a fractional power is calculated by introducing bosonic fields (pseudofermions), and sandwiching this Dirac operator raised to minus said fractional power between them. This fractional power of the Dirac operator is approximated to machine accuracy by a rational approximation. After defining this this theory on a discrete space-time lattice, the inversions required by the partial-fraction expansion of the rational approximation are performed using Krylov space methods, in particular a multi-shift extension of the conjugate gradient algorithm. A global Metropolis Monte-Carlo accept/reject step applied at the end of each trajectory removes discretization errors introduced by the numerical integration of these stochastic equations of motion. We parallelize the code by assigning a fixed number of adjacent lattice sites to each MPI task. Network bandwidth ultimately limits how small a chunk of the lattice can be assigned to each task. Experience with benchmarking this code on a variety of lattice sizes indicates that we should expect a performance of approximately 3 Gflops/core for a 24^3*8 lattice running on 192 cores, i.e. around 550 to 600 Gflops. In each case we have checked, this per core performance remains nearly constant as the number of cores is varied, so that maximum throughput is achieved at the largest number of cores allowed by the current implementation (in this case 192). Current: undetermined amount Justification: The per core performance for the 24^3*8 runs is approximately 3 Gflops on 192 cores. Althought we have not performed such a detailed analysis as for the 24^3*12 lattice, we expect at worst a linear speedup from the minimum number of cores (8) to the maximum number of cores (192). We note that the single node environment -- size and shape of the sublattice and communication pattern -- is identical for these 2 lattice sizes, which is why a separate performance analysis is unnecessary. This code has been running effectively on Fusion since it was released to the user community. We will be concentrating on the 2-flavour runs on 24^3*8 lattices with m=0.0025 on Fusion. Each run is expected to take approximately 60 wallclock-hours, and we are budgeting for 80 such runs. We are not providing detailed scaling analysis, since this was provided in previous years, and the code is unchanged. The main enhancement we have planned for this year is to rearrange the task to node assignments to assign a 24^2*4*2 section of the lattice to each node, rather than the default 24^2*8*1 section, by setting MPICH_RANK_REORDER_METHOD=3 and providing an appropriate MPICH_RANK_ORDER file. This will reduce the communication overhead. Any reduction of CPU time obtained by this enhancement will be used to finish our current project on a 16^3*8 lattice using 128 cores. Requested: 250000 A specific reason has been given: I have exhausted my current allocation, but the project is not yet completed. Note that my original request was for 960000, and my allocation was only 250000. This needs to be approved and the final allocation amount decided upon. Thank You, The LCRC Accounts System

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[LCRC Accounts] Project Allocation Request
by accounts＠lcrc.anl.gov 08 Jan '13

08 Jan '13

Hello, A change in allocation has been requested: Requester: ssom (Sibendu Som) Project: spray-modeling Title: Development of a near nozzle spray modeling approach Description: The project is divided into 5 major tasks to be performed in 3 years in collaboration with Convergent Science Inc., and Cummins Engine Company: Task 1: Development and validation of a nozzle flow model to account of transient effects such as needle movement, needle off-axis motion, rail pressure fluctuations etc. Task 2: Further advancement of KH-ACT (Kelvin Helmholtz – Aerodynamic Cavitation Turbulence) primary breakup model to calculate more accurately relevant length and time-scales for the cavitation, turbulence, and aerodynamically induced breakup processes. Task 3: In the past nozzle flow and spray simulations have been statically coupled. A dynamic coupling approach will be developed so that the nozzle flow simulations can influence the spray development and vice versa. This is quite complicated since the length and time scales associated with nozzle flow processes are significantly different from spray processes. Task 4: An one equation non-viscosity dynamic structure model large eddy simulation (LES) based turbulence modeling approach will be implemented in CONVERGE. Grid-convergence on critical spray parameters will be evaluated with the implemented LES models. Task 5: Implementation of an Eulerian-Lagrangian spray model: While dynamic coupling of the nozzle flow and KH-ACT models will enhance the accuracy of spray simulations, a transition between the Eulerian and Lagrangian phases must take place at the nozzle exit with this approach. Moving the transition point downstream allows for a more natural bridge between the coupled simulations as the liquid fuel is modeled in an Eulerian framework on both sides of the nozzle exit. A specific challenge of this task is developing an algorithm to convert the Eulerian liquid to Lagrangian parcels outside of the dense spray region. Current: undetermined amount Justification: Requested: 100000 A specific reason has been given: The allocated time was lower than the original request during the committee meeting. Also new personal have joined the group and performing simulations which has increased the need for more core hours. This needs to be approved and the final allocation amount decided upon. Thank You, The LCRC Accounts System

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