September 2015 - Allocations-admins - mailman3.cels.anl.gov

[LCRC Accounts] Yearly Allocation Request for AWA-beam-dynamics
by accounts＠lcrc.anl.gov 14 Sep '15

14 Sep '15

Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Nicole Neveu Project Name: AWA-beam-dynamics Division: HEP Project title: High Accuracy Beam Dynamic Simulations Associated funding: Other Systems: Science: This project uses OPAL, a tool for charged-particle optics in accelerator structures and beam lines. In particular, we will use OPAL-T which can be used to model beam lines, linacs, rf-photo injectors and complete XFEL’s excluding the undulator. Realistic 3D beam dynamics simulations are used so that effects of couplers, vacuum pumping chambers, and other asymmetric features can be modeled. Project description: We intend to use this model to study the 3D effects of various asymmetric beamline components that cannot be accurately modeled in the usual 2D codes. Unlike 2-dimensional codes, OPAL is not restricted in the kind of geometry it can model. It is therefore possible to consider arbitrary shapes and their inclusion in beam dynamics and particle tracking calculations. Further, we plan to develop OPAL-T beyond its current capabilities to include realistic wakefield effects. Current wakefield effects are calculated with the rigid bunch approximation which is valid when the wakefield is weak and the beam is rigid. In the case of the Argonne Wakefield Accelerator (AWA) this assumption is not valid since the wakefield is very strong and the beam energy is low. The OPAL codes work very efficiently on parallel processors. It uses MPI and has demonstrated good speed-up efficiencies for over 1000 CPU's on the Cray XT5 at the Swiss Center for Scientific Computing. Industry partnership: Project URL: Current FY Hours Used: undetermined amount New FY Requested allocation: 50000 Q1: 50000 Q2: 0 Q3: 0 Q4: 0 Justification: Storage requirements: Thank You, The LCRC Accounts System

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[LCRC Accounts] Yearly Allocation Request for gm_gasexchange
by accounts＠lcrc.anl.gov 14 Sep '15

14 Sep '15

Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Sibendu Som Project Name: gm_gasexchange Division: ES Project title: Modeling Gas Exchange in the GM TCC Engine using LES Associated funding: LDRD funding for Argonne, GM funding for GM and Univ. of Michigan Other Systems: GM R&D Science: This project will use an Eulerian-Lagrangian Computation Fluid Dynamics (CFD) software called CONVERGE to model the gas exchange process in an engine. The primary objective of the proposed research is to characterize the cyclic variability in internal combustion engines (ICE) as a result of gas exchange processes. This study will determine the minimum grid size and the number of cycles to be simulated such that the mean flow field and cyclic variabilities predicted by large eddy simulation (LES) are similar to those measured from experiments. Project description: The project is divided into three parts: In the first part, large eddy simulation (LES) will be used to model 50 consecutive cycles of the GM transparent combustion chamber (TCC) engine with a base grid size of 0.5 mm. The mean and variance of the predicted flow field will be compared to the LES results performed previously with a base grid size of 1 mm, and also to the PIV measurements. This study will determine the minimum grid size and the number of cycles to be simulated such that the mean flow field and cyclic variabilities predicted by large eddy simulation (LES) are similar to those measured from experiments. In the second part of the study, more insights into the reasons for the cyclic variability will be developed by repeating the simulation at different engine speeds and different intake manifold pressures. In the final part of this study, LES predictions will be improved by implementing improved models for the treatment of the near-wall flows, as this could strongly influence the in-cylinder flow. Industry partnership: General Motors - Research and Development Group Project URL: http://verifi.anl.gov/ Current FY Hours Used: undetermined amount New FY Requested allocation: 600000 Q1: 150000 Q2: 150000 Q3: 150000 Q4: 150000 Justification: During the past four years, we have been working in close collaborations with the developers of CONVERGE code to ensure that it scales well both on clusters and super-computers. We have implemented METIS algorithm which enables us to load balance significantly better than the original load balancing in CONVERGE. This was the first step towards enabling CONVERGE code for HPC use. In collaboration with researchers at ALCF (during the past couple of years), we have further performed scaling studies with the code on Mira. Based on implementation of MPI-I/O, advancements in chemistry calculation with a stiffness based load balancing criteria and CFD load balancing, we have been able to show good scaling of the CONVERGE code on Mira on up to 4096 processors for a closed cycle engine simulation with about 10 million cells. These advancements were showcased during the VERIFI workshop in Nov. 2014 and we have published a detailed paper highlighting these changes. The a bove changes are not only expected to benefit calculations on Mira but also help on computing clusters like Fusion and Blues. More details and paper can be made available on request. Storage requirements: 2 TB Thank You, The LCRC Accounts System

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[LCRC Accounts] Yearly Allocation Request for SprayFlame-LES
by accounts＠lcrc.anl.gov 14 Sep '15

14 Sep '15

Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Muhsin Ameen Project Name: SprayFlame-LES Division: ES Project title: Development of sub-grid turbulent combustion models for LES under engine conditions Associated funding: Strategic Initiative LDRD project, NSF-DOE project Other Systems: Science: This project will use an Eulerian-Lagrangian Computation Fluid Dynamics (CFD) software called CONVERGE to model reacting spray flames under diesel engine conditions. The primary objective of the proposed research is to examine the role of turbulent-chemistry-interaction (TCI) when coupled with large eddy simulation (LES) under engine conditions and to develop turbulent combustion models which are universally applicable to mixed regimes of combustion, including premixed and non-premixed flames with local ignition and extinction. This objective will be achieved through a collaborative effort by combining computational flame diagnostics, turbulence modeling, direct numerical simulation (DNS), LES and Reynolds averaged Navier-Stokes simulation (RANS). The model development will be primarily based on chemical explosive mode analysis that can rigorously detect limit flame phenomena and elementary flamelets. Project description: The project is divided into two parts: In the first part, a methodology to track the premixed flame front based on chemical explosive mode analysis and adaptive mesh refinement, which was developed as part of the NSF/DOE project will be validated. This will be done by performing large eddy simulation (LES) of an impulsively started jet, and comparing the statistics of the flame development with a direct numerical simulation (DNS) database which is being generated at Sandia national laboratory. In the second part of this study, the flame front tracking methodology will be applied to model the ECN Spray A, which is a spray flame under conditions similar to diesel combustion. Parametric sweep of ambient temperature and ambient oxygen concentration will be performed with the new methodology. It is expected that the new methodology will lead to improved predictions of the flame development. Industry partnership: The project is between Argonne, UCONN and Sandia. It is expected that the results of the project will not only advance the state-of-the-art in LES combustion calculations but also significantly benefit industry research. Argonne will be performing the algorithm development, simulations, post-processing results, and writing technical reports. Sandia and UCONN will perform DNS study with simplified geometry and boundary conditions from Argonne’s work and provide feedback to Argonne. The models will be implemented in CONVERGE code owned by the software vendor CSI. Project URL: http://www.transportation.anl.gov/engines/multi_dim_model_home.html Current FY Hours Used: undetermined amount New FY Requested allocation: 499999 Q1: 125000 Q2: 125000 Q3: 125000 Q4: 124999 Justification: Storage requirements: 3 TB. We have been allocated 3 TB for this project since the last few months. The size of the data generated from the current simulations is too large, and we require 3 TB for our requirements. Thank You, The LCRC Accounts System

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[LCRC Accounts] Project Request: iro-catal
by accounts＠lcrc.anl.gov 13 Sep '15

13 Sep '15

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: Fatih Sen Applicant's institution: ANL Applicant's division: NST Project Name: iro-catal Project title: Computational IrO2 catalyst design Associated funding: LDRD Other Systems: We have 420000 core hours at Carbon cluster at Center for Nanoscale Materials Science: Iridium oxide is one of the most efficient electrocatalysts for the oxygen evolution reaction (OER) in the water splitting process, for efficient solar energy into fuel (H2) conversion. Atomistic modeling of IrO2 is critical for understanding the structure, chemistry, and nanoscale dynamics of IrO2 in these applications. In previous studies, the size and shape of nanoclusters has been reported to have significant affect on the catalyst performance as a result of change in the local atomic coordination at the nanocluster surfaces, edges and corners. These studies however, are mostly focused on metallic nanoclusters, but the atomistic mechanisms of catalytic activity change with size and shape of oxide nanoclusters are yet to be determined. We have previously developed a first principles based Morse + QEq (MS-Q) variable charge force field for this technologically important Ir-O system that can predict the catalytic activity and structural stability of IrO2 nanoclusters in water splitting and OER. In this project, we will carry out molecular dynamics calculations using the MS-Q to reveal the shape and size affects on the catalytic activity of IrO2 nanoclusters. DFT calculations will be simultaneously performed to estimate the surface and nanocluster stability for selected systems for comparison. Project description: The DFT calculations on IrO2 surfaces and selected nanoclusters will be carried out using the plane wave code VASP available in both Fusion and Blues. The PBE exchange correlation and Hubbard U correction, as well as the projector augmented wave (PAW) method, will be used. All calculations will be carried out including spin polarization and spin orbit coupling. Classically molecular dynamics calculations will be carried out using the GULP software with the previously developed MS-Q force field. The details of the calculations can be listed as: i) DFT calculations will be carried out to study surface stability and catalytic activity of water splitting reaction and OER on IrO2 surfaces. We identified 20 different surface structures and we will consider at least 3 different adsorption sites on each surface. Each of these calculations are estimated to take 30 hours on 64 cores. The total request for this part is 30 * 64 * 3 * 20 = 115, 200 core hours. ii) To evaluate the stability, and catalytic activity of iridium oxide nanoclusters, molecular dynamics (MD) simulations will be carried out for different cluster sizes and shapes. Approximately 100 MD simulations will be carried out considering all different type of clusters and adsorption sites. The time estimated for each simulation is 100 hours in 16 cores. The total request for 100 MD simulations is: 100 * 16 * 100 = 160,000 core hours. iii) For selected small nanoclusters (< 500 atoms), we will carry out five DFT calculations to predict the catalytic activity and compare with the MS-Q force field. Each large scale DFT calculation is expected to take 4 days on 256 cores, which will require a total of 4 * 24 * 256 * 5 = 122,880 core hours. Industry partnership: Project URL: Requested allocation: 400000 Q1: 0 Q2: 0 Q3: 0 Q4: 400000 Justification: Storage requirements: 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] Project Request: FF-opt
by accounts＠lcrc.anl.gov 13 Sep '15

13 Sep '15

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: Fatih Sen Applicant's institution: ANL Applicant's division: NST Project Name: FF-opt Project title: Comparison of optimization algorithms for force field fitting Associated funding: LDRD Other Systems: Science: Accurate description of atomic processes such as catalytic activity or reaction kinetics with empirical force fields strongly depends on the force field parameterization process. An empirical force field gives the total energy (E) of a system of atoms based on the positions of each atom, i.e. E=f({a_i},{r_n}), where f is a function that describes the interaction, {a_i} represents the set of parameters, and {r_n} the set of atomic positions. The determination of force-field parameters {a_i} for various complex functional forms requires a systematic approach, which can enable sampling of most of the available parameter space. In this project, we will explore different local and global optimization algorithms in the optimization of force field parameters including single and multi-objective genetic algorithms, and compare the effectiveness of different algorithms in the parameterizing of different functional forms. In terms of local optimization, we wil l test the commonly used Simplex and Levenberg-Marquardt (L-M) methods that are known to perform reasonably well for many non-linear least-squares problems. In addition to these common methods, in collaboration with Wild Group at MCS, we will use a more sophisticated derivative-free method for non-linear least squares problems as implemented in POUNDERS and ORBIT. Local optimization methods rely greatly on the initial guess for the unknown parameters and fails for very complex functional forms. To cover all of the parameter phase space, a large number of starting guesses needs to be evaluated. On the other hand, global optimization methods comprehensively search suitable regions of parameter space and can be more suitable for force-field parameterization. Here, we will employ evolutionary algorithms namely genetic algorithms (GA) in force field fitting, which are reported to exhibit unbiased, and a more global search by maintaining a diverse population, hence discovering potentially good regions of interest. In all local and global optimization schemes, the goodness of fit and hence, the predictive capability of the force field, depends on the weighting scheme selected between different observables. The selection of weights is typically based on the difference in the numerical values and total number of different quantities, and also based on the subjective determination related to the problem of interest. One way of removing the weighting effects is to use a multi-objective optimization algorithm, which can give a set of solutions at the Pareto front and enable the selection of force field parameters according to desired properties. We will explore the applicability of multi-objective GA for determining force field parameters and compare the results with single-objective GA. Project description: The comparison of different optimization algorithms will be carried out on using an existing training dataset obtained from density functional theory calculations (DFT) using the VASP code, which contains binding energies, elastic constants, lattice constants and internal coordinates for various IrO2 polymorphs. We are planning to explore 3 different functional forms (f), namely Morse, Morse+QEq and Tersoff, as implemented in the GULP software. The test of Simplex and L-M will be done using the program codes implemented in Numerical Recipes and MINPACK. These codes essentially work in serial, but we will employ multi-start algorithms to run different initial guesses in parallel. The POUNDERS and ORBIT algorithms will be tested as implemented in the PETSc code available in LCRC resources. For single- and multi-objective genetic algorithms, we will use the PyGMO program, which is already installed in the Blues system. PyGMO can be efficiently (100%) pa rallelized over the population size used. The details of the calculations can be listed as: i) We will compare different optimization techniques for force field parameters with different functional forms. We are planning to use 500 initial guess parameter set for the Simplex and L-M algorithms. For Simplex, each optimization calculation takes 4 hours in 16 cores. For L-M, each optimization calculation takes 2 hours in 16 cores. So, in total we will require 3*500*(16*2+16*4) = 144,000 core hours. ii) In single objective GA tests, we are going to investigate effect of population size (4 different population size of 100, 200, 400, and 1000) on the ability of the potential parameters to reproduce DFT results, and the speed of convergence. On average, each GA run is estimated to require 60 hours on 128 cores. So the calculations will require 2*3*4*60*128= 184,320 core hours. ii) In multi-objective GA tests, we are going to investigate effect of population size (4 different population size of 100, 200, 400, and 1000). On average, each GA run is estimated to require 60 hours on 128 cores. This part of the project will therefore require 2*3*4*60*128= 92,160 core hours. Total computation time requested: 420,000 core hours. Industry partnership: Project URL: Requested allocation: 420000 Q1: 0 Q2: 0 Q3: 0 Q4: 420000 Justification: Storage requirements: 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] Project Request: VO2_thermal
by accounts＠lcrc.anl.gov 13 Sep '15

13 Sep '15

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: Alper Kinaci Applicant's institution: ANL Applicant's division: NST Project Name: VO2_thermal Project title: Evaluation of thermal transport in bulk and nanostructured VO2 Associated funding: This work is funded by a Strategic Partnership Project (previously known as Work-for-Others) sponsored by the Toyota Motor Engineering & Manufacturing North America (TEMA). Other Systems: Carbon cluster at Center for Nanoscale Materials (CNM) at Argonne: 522,000 core hours Science: Metal to insulator transition (MIT) refers to a sharp switch in the electrical conductivity of a material. This phenomenon can be introduced by electron localization [1, 2], carrier doping and electron-phonon coupling [3]. The actual driver of this transition is still in debate in different materials since the drastic change in conductivity is accompanied by a distortion in the lattice (and generally a phase transformation) [4]. Among materials possessing MIT, VO2 is heavily studied in terms of its electronic properties since its transition occurs close to room temperature. The semiconductor phase below 340K has a monoclinic structure while the metallic phase above 340K has a rutile structure [5]. During the transformation between these phases electrical conductivity changes about 4 orders of magnitude [6]. In contrast to electrical conductivity, the thermal transport in VO2 has not been given the same attention. Practically, the electronic part of the thermal conductivity maybe estimated from Wiedemann-Franz law. Accordingly, we will focus on the theoretical estimation of the phonon part of the thermal transport. In order to characterize lattice heat transport in different phases of VO2, we will employ molecular dynamics (MD) simulations. The predictive power of MD calculations depends heavily on the empirical potential parameters. Several empirical potentials for VO2 exist in the literature; however, they were parametrized to represent bulk structural properties and oxidation thermodynamics of tetragonal VO2 [7], and fail to reproduce DFT phonon and elastic properties. In this proposal, we will develop an empirical potential that can represent phonon dispersions, elastic properties, surface and defect formation energies of the two VO2 phases. The Buckingham potential plus coul omb interactions form is selected to represent the interactions. The training set, which will include the aforementioned properties, will be generated from density functional theory calculations. The parameter fitting will be accomplished with a genetic algorithm global optimizer. The resultant interatomic potential will be used in molecular dynamics calculations to evaluate lattice thermal conductivity of bulk and nanostructured VO2. The direct method, in which a temperature gradient is imposed on the system [8], and Green Kubo method, in which the heat current is obtained from equilibrium fluctuations of energy [9, 10], will be utilized to calculate thermal conductivity. With the same procedure, we will systematically evaluate the effects of substitutions, point defects, and film thickness on the thermal transport of VO2 phases. The results of these calculations will guide the experimental efforts and ultimately lead to effective tuning of the thermal transport in VO2-base d MIT materials. [1] P. W. Anderson, Phys. Rev. 109, 1492 (1958). [2] N. F. Mott, “Metal-Insulator Transitions” (Taylor and Francis, London 1990). [3] G. Gruner, Rev. Mod. Phys. 60 1129 (1988). [4] A. Perucchi, L. Baldassarre, P. Postorino and S. Lupi, J. Phys.: Condens. Matter 21, 323202 (2009). [5] R. M. Wentzcovitch, W. W. Schulz and P. B. Allen, Phys. Rev. Lett. 72, 3389 (1994). [6] F. J. Morin, Phys. Rev. Lett. 3, 34 (1959). [7] B. Jeon, C. Ko, A. C.T. van Duin, and S. Ramanathan, Surface Science, 606, 512 (2012). [8] P. K. Schelling, S. R. Phillpot, and P. Keblinski, Phys. Rev. B 65, 144306 [9] M. S. Green, J. Chem. Phys. 22, 398 (1954). [10] R. Kubo, J. Phys. Soc. Japan 12, 570 (1957). Project description: The calculations will involve the items below. (1) Density functional theory (DFT) calculations will be employed to obtain the training set that will be used to parameterize the empirical potential. This set will include the phonon dispersions, elastic constants, and surface and vacancy formation energies. The surface energies will be computed using large slab configurations with at least 2 slab thicknesses. We will evaluate 5 low index surfaces. For the vacancies, we will compute both vanadium and oxygen vacancy formation energies. All these calculations will be done for both VO2 phases. (2) A Buckingham potential plus a Coulomb potential will be parameterized to fit the DFT training data generated in (1). In parameterization, a genetic algorithm global optimizer is used in conjunction with local optimizers e.g. simplex and conjugate gradient. We estimate 20 trials before the parameter set converges to give a reasonable representation of the training set. (3) The parametrized potential will be used to test the convergence of thermal conductivity in pristine VO2 phases. From previous experience, we estimate that 30,000-60,000 atoms will be sufficient to capture enough long wavelength phonons that are important for thermal transport. Each thermal transport calculation will be repeated 4 times starting from different initial conditions (i.e. different initial velocity distributions) to obtain a reasonable ensemble average. The simulation time step will be 1 fs. Depending on the method of evaluation (direct method or Green-Kubo), simulations should continue about 1 to 5 million steps (corresponding to 1 to 5 ns) before calculation of thermal conductivity. (4) In the bulk forms, the effect of vacancies (oxygen and vanadium) and metal substitutions (i.e. to be treated as mass differences) will be investigated with 3 different concentrations in both phases. The time step, total number of time steps and number of different initial conditions for each system will be same as the ones in (3). Both monoclinic and tetragonal phases of VO2 will be considered. (5) Lattice thermal conductivity of thin films of VO2 will be investigated. The film thicknesses and sizes will be set according to experimental needs. Here we estimate thermal conductivity calculations for 3 different film thicknesses. The number of atoms in these systems can be larger than bulk systems and will be adjusted depending on the experimental needs. Apart from number of atoms, a similar set up will be used for the calculations as given in (4) and (5) The DFT calculations will be performed using the plane wave code VASP, with GGA-PBE exchange correlation functional, projector augmented wave (PAW) treatment of core electrons and Hubbard correction (U). The VASP code is tested in Blues with a 350 electron system and 65%-80% scaling efficiency is obtained 64 to 128 cores compared to 16 cores. In Fusion where the code has been tested for systems having up to 7000 electrons, the code showed 70%-80% scaling efficiency for 64 to 128 cores compared to 8 cores. Given this performance, the VASP code has the efficiency to simulate large number configurations in reasonable amount of time. For the optimization process, we will use a multi-objective genetic algorithm toolbox which is developed at University of Illinois Urbana-Champaign. The code has a 100% scaling efficiency in single node (8 cores on Fusion and 16 cores on Blues). Molecular dynamics calculations will be carried out with LAMMPS code. This code is tested on Fusion for a ~13000 atom system using a Buckingham + point charge force field. A scaling efficiency of 87% is obtained for 64 cores compared to 8 cores. Preliminary testing shows that an MD simulation of 30,000 atoms and 1 million time steps require 30 hours on 64 cores. Therefore, we estimate that thermal conductivity calculations require 2000 core-hours on average. The time estimates for the various parts of our proposal considering the computational efficiencies are listed below. (1) a- Evaluation of phonon dispersions and elastic constants: 10 calculations x 640 core hours each = 6,400 b- Evaluation of vacancy (vanadium and oxygen) formation energies: 10 calculations x 640 core hours each = 6,400 c- Evaluation of surface energies: 20 calculations x 1280 core hours each = 25,600 (2) Force field optimization: 20 calculation x 2,000 core hours each = 40,000 (3) Thermal conductivity calculations in bulk phases: 8 calculations x 2,000 core hours each = 16,000 (4) Thermal conductivity calculations on defected systems: 108 calculations x 2,000 core hours each = 216,000 (5) Thermal conductivity calculations in VO2 thin films: 24 calculations x 5,000 core hours each = 120,000 The total request is 430,400 core-hours. Dr. Alper Kinaci and Dr. Maria Chan will be responsible for carrying out the simulations. Industry partnership: The project is funded by TEMA and is part of an ongoing partnership between Argonne and Toyota in the experimental and computational investigations of novel ways to control thermal transport Project URL: Requested allocation: 50000 Q1: 0 Q2: 0 Q3: 0 Q4: 50000 Justification: Storage requirements: 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 for biodiesel-combustion
by accounts＠lcrc.anl.gov 12 Sep '15

12 Sep '15

Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Sibendu Som Project Name: biodiesel-combustion Division: ES Project title: Computation Fluid Dynamics Modeling of Petrodiesel and Biodiesel Associated funding: DOE office of vehicle technology Other Systems: University of Connecticut Science: This project will use an Eulerian-Lagrangian Computation Fluid Dynamics (CFD) software called CONVERGE to model various diesel engine processes like internal nozzle flow, spray behavior, combustion and emission processes. The goal is to capture the differences between diesel and biodiesel fuels from a CFD standpoint since computer based modeling is more cost effective than performing full scale laboratory experiments. Project description: The project has previously developed a multi-component diesel fuel surrogate for compression ignition (CI) engine applications with great potential. It is more representative of diesel fuel due to an important chemical class present and has been requested by several research institutes worldwide. In the coming year, the project will focus on developing a 5-component diesel fuel surrogate for CI engine applications. The single-cylinder engine performance and emission data from Sandia National Laboratory will be used to further develop and validate spray and combustion models in CONVERGE and perform parametric studies. The major motivation is to develop more predictive and robust sub-models for capturing diesel engine combustion processes. In addition, predictions using biodiesel fuel surrogate will be compared with the diesel fuel surrogate to evaluate the performance of the fuels. Lastly, fundamental studies will be performed to understand ignition and f lame stabilization characteristics of diesel flame at engine conditions using CONVERGE. Comparison will be performed between inner nozzle flow, non-evaporating and evaporating spray, combustion characteristics, engine performance and emission characteristics of biodiesel and diesel. Industry partnership: Project URL: http://www.transportation.anl.gov/engines/multi_dim_model_home.html Current FY Hours Used: undetermined amount New FY Requested allocation: 475000 Q1: 100000 Q2: 125000 Q3: 125000 Q4: 125000 Justification: Storage requirements: 1 TB Thank You, The LCRC Accounts System

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[LCRC Accounts] Yearly Allocation Request for GasTurbineCombustion
by accounts＠lcrc.anl.gov 12 Sep '15

12 Sep '15

Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Sibendu Som Project Name: GasTurbineCombustion Division: ES Project title: Computation Fluid Dynamics Modeling of Soot Associated funding: DOE office of vehicle technology Other Systems: Convergent Science Inc. Science: This project will simulate the combustion process at gas turbine engine conditions using an Computation Fluid Dynamics (CFD) software called CONVERGE to develop sub-models for combustion and emission processes. The goal is to develop subgrid combustion models and detailed soot models for large eddy simulation (LES) of engines since LES is believed to provide more accurate predictions than Reynolds-averaged Naiver-Stokes (RANS) model. Project description: The project has previously demonstrated that the LES-based predictions provides much more accurate results than RANS on spray, combustion and emissions at engine conditions, especially for soot predictions although the soot model is rather simple. The better estimation for LES is believed to be due to the better-resolved soot precursor, C2H2. In our next step, several more detailed soot models with PAH species as soot precursor will be studied. These more detailed soot models will provide more detailed information, such as soot number density etc., and also is believed to better mimic the soot formation and oxidation processes. We plan to collaborate with UCONN to develop a reduced chemical mechanism for n-dodecane that has PAH sub-mechanism (from KAUST) for engine applications. With this chemical kinetic model, a systematic study will be conducted, including mesh resolution, soot precursor, turbulence model, combustion model effects, etc. The soot measu rements in a constant-volume combustion chamber from Sandia National Laboratory will be used to further develop and validate combustion and soot models in CONVERGE and perform parametric studies. The major motivation is to develop more predictive and robust sub-models for capturing the soot formation and oxidation processes. Industry partnership: Project URL: http://www.transportation.anl.gov/engines/multi_dim_model_home.html Current FY Hours Used: undetermined amount New FY Requested allocation: 475000 Q1: 100000 Q2: 125000 Q3: 125000 Q4: 125000 Justification: Storage requirements: 1 TB Thank You, The LCRC Accounts System

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[LCRC Accounts] Yearly Allocation Request for Wind_turbine_LES
by accounts＠lcrc.anl.gov 11 Sep '15

11 Sep '15

Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Shashi Aithal Project Name: Wind_turbine_LES Division: CELS Project title: High-fidelity LES simulation of wind-turbine flow-fields Associated funding: Other Systems: Science: The project is focused on the application and validation of a novel filtered turbulence model (DLRM) to the fluid dynamic simulation of the wind-turbine wake, in order to predict its characteristics (pressure coefficient as a function of time and power generated). Project description: In FY2015, a Master's thesis was completed at Politecnico di Milano that investigate the flow field around a H-type Darrieus vertical-axis wind turbine. This work presented an external-aerodynamics test-case for DLRM. This turbulence model operates in URANS or ILES mode, depending on the comparison of the modeled scales to what can potentially be resolved by the computational grid and time-step. The flow was fully turbulent with the wind-turbine being characterized by a tip-speed ratio λ = 1.5, which corresponds to a low-load condition. A highly resolved computational grid was used for discretizing the computational domain (≈ 45 M cells). This fine resolution was necessary in order to reproduce a non-confined environment for the airstream. The convergence characteristics of this grid was studied a part of the thesis. In FY16, the PIs plan to develop a more non-uniform grid with reduced resolutions in far-field regions as indicated by the earlier simulations to obtain fully converged solutions for detailed data analyses. We plan to run various simulations with different degrees of resolution to obtain an optimum mesh. Approximately 20-30 runs each taking 8 to 10,000 core-hours are anticipated for this project Industry partnership: None Project URL: Current FY Hours Used: undetermined amount New FY Requested allocation: 200000 Q1: 25000 Q2: 75000 Q3: 25000 Q4: 75000 Justification: Storage requirements: Thank You, The LCRC Accounts System

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[LCRC Accounts] Yearly Allocation Request for cavitation-modeling
by accounts＠lcrc.anl.gov 11 Sep '15

11 Sep '15

Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Sibendu Som Project Name: cavitation-modeling Division: ES Project title: CFD Modeling of Internal Flow of Injectors and One-Way Coupling Spray Simulations Associated funding: DOE - Office of Vehicle Technologies Other Systems: Cummins Inc., Convergent Science Inc. Science: This project will use the VOF-based Eulerian model and HRM cavitation model in an computation fluid dynamics (CFD) software called CONVERGE to model the internal flow and cavitation phenomena in IC engine injectors under various injection conditions, and provide boundary conditions for performing Lagrangian-Euerian spray modeling in CONVERGE in a one-way coupling approach. The goal is to understand the flow dynamics and cavitation in injectors and facilitate the Lagrangian spray simulation in a one-way coupling approach. Project description: The project is in two parts: In the first part, the work will focus on both RANS and high-fidelity, multi-realization LES calculations of diesel injectors from the Engine Combustion Network (ECN) and APS at Argonne. The objective is to study the needle motion effect on cavitation occurrence, hole-to-hole variation, cycle-to-cycle variation, and the internal flow effect on the exiting spray dynamics. In the second part, the validation of the implemented one-way coupling spray model will be performed with experimental data. The objective is to achieve accurate spray simulation by including the information from nozzle flow and computational time saving. The model will be used to study multi-hole injectors and nozzle k-factor effects on sprays. Industry partnership: Project URL: http://www.transportation.anl.gov/engines/multi_dim_model_home.html Current FY Hours Used: undetermined amount New FY Requested allocation: 475000 Q1: 125000 Q2: 100000 Q3: 125000 Q4: 125000 Justification: Storage requirements: 1 TB Thank You, The LCRC Accounts System

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