July 2014 - Allocations-admins - mailman3.cels.anl.gov

New LCRC report submitted for Nek5000
by support＠lcrc.anl.gov 31 Jul '14

31 Jul '14

Full project report at https://accounts.lcrc.anl.gov/reporting/project/2014/?project=Nek5000

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New LCRC report submitted for PETSc-Foam
by support＠lcrc.anl.gov 31 Jul '14

31 Jul '14

Full project report at https://accounts.lcrc.anl.gov/reporting/project/2014/?project=PETSc-Foam

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[LCRC Accounts] Project Allocation Request
by accounts＠lcrc.anl.gov 31 Jul '14

31 Jul '14

Hello, A change in allocation has been requested: Requester: dduke (Daniel Duke) Project: XRayFuelSpray Title: Fuel Injection and Sprays Studied Using X-Ray Diagnostics Description: Computational Fluid Dynamics using the OpenFOAM framework has been employed to simulate cavitating turbulent fluid flow in both simplified nozzles and diesel fuel injectors, with the purpose of supporting and informing x-ray radiography and phase-contrast measurements performed at the Advanced Photon Source. A number of state-of-the-art numerical solvers have been implemented in OpenFOAM; namely incompressible-liquid and fully compressible homogeneous relaxation cavitation models and more recently a noncondensible-gas fully compressible homogeneous relaxation cavitation model. These codes were developed by Schmidt et al at the University of Massachusetts-Amherst. In the last year, we have switched from using OpenFOAM’s built-in solvers for multiphase flow to a dedicated cavitation code (HRMFoam) developed by Professor David Schmidt. The homogeneous relaxation model (HRM) assumes that when vapor is present, the vapor and liquid are homogeneously mixed within the local cell, but are not at thermodynamic equilibrium. The equilibrium state is not computed using an equation of state but is instead determined from a lookup table formulated using NIST REFPROP data. The HRM model has successfully been employed to simulate the effect of varying gasoline-ethanol blended fuels in a cavitating polycarbonate nozzle, and the results were favorably compared to x-ray radiography measurements performed at the Advanced Photon Source. Further high-resolution large eddy simulations of the polycarbonate nozzles used at APS are need to be undertaken in the following year. Scalability of HRMFoam simulations is good up to approx. 72 processors (the capacity of our dedicated nodes). We need to run multiple simulations at various boundary conditions, thus the need for additional allocation beyond the use of the dedicated nodes. Several improved solvers are currently under development which over the next year will allow for the modeling of a non-condensible gas phase, to simulate the difference between a ‘submerged’ cavitating flow and a cavitating flow issuing into a gaseous environment, as is the case for fuel injection in engines. Compressible modeling is also being investigated through both HRM and also alternative compressible fluid solvers. Currently, HRM assumes the liquid phase to be incompressible. Although this has shown good results in comparison with experimental data, given the extremely high pressures involved in fuel injection (greater than 1500 bar) bulk compressibility of the fuel will not be insignificant. Further development is occurring within the OpenFOAM framework and we do not expect to need any additional software installed on Fusion to achieve these goals. Our allocation for the following year will need to be maintained at the current level to achieve the above goals. No increase in allocation is required. We expect that less than 1% of the allocation will be single-core jobs (of which most are file I/O and cleanup tasks at the start and end of parallel jobs). Current: undetermined amount Justification: 6*12 processor dedicated nodes have been purchased on FUSION to support these studies. Requested: 60000 A specific reason has been given: Our group has had to take on a new staff member at rather short notice who is going to be using the LCRC account. He needs to get started doing simulations right away, but there is not enough allocation in our project bank to accommodate his work before the next years' allocations are made.We require an increase in the number of core-hours on Blues/Fusion to see us through to October. Right now, our project (XRayFuelSpray) has about 79k core hours remaining, and we need an extra 60k so that our new group member can do his simulations. If this is not possible, then any smaller amount would still be helpful. In the previous quarter, we didn't use our complete allocation due to staffing changes and other disruptions to our group's activities. This quarter, we are overstretched and will exceed our allocation. We intend to provide a justification in our next proposal for the need to increase our allocation to accommodate our new group members' work. The nature of the additional w ork will involve simulations of natural gas fuel injection systems using Converge software; these simulations will support our research program at APS. If you require further information please contact Daniel Duke (dduke(a)anl.gov) and we will be happy to provide it. This needs to be approved and the final allocation amount decided upon. Thank You, The LCRC Accounts System

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New LCRC report submitted for XRayFuelSpray
by support＠lcrc.anl.gov 29 Jul '14

29 Jul '14

Full project report at https://accounts.lcrc.anl.gov/reporting/project/2014/?project=XRayFuelSpray

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New LCRC report submitted for MRSA
by support＠lcrc.anl.gov 29 Jul '14

29 Jul '14

Full project report at https://accounts.lcrc.anl.gov/reporting/project/2014/?project=MRSA

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[LCRC Accounts] Project Allocation Request
by accounts＠lcrc.anl.gov 29 Jul '14

29 Jul '14

Hello, A change in allocation has been requested: Requester: ssom (Sibendu Som) Project: cfd_enginemodeling Title: Computation Fluid Dynamics Modeling of Diesel Engine Processes Description: The project is divided into three major phases: 1) Cavitation modeling: A two-phase cavitation modeling approach using the homogeneous relaxation method has been developed and implemented in CONVERGE. Extensive validation of the new model will be performed against experimental data available in literature and new data from Advanced photon source at Argonne. 2) Spray Modeling: Traditional Eulerian-Lagrangian spray modeling approaches are hampered by the fact that the results are not grid-independent. Grid-convergent spray modeling approaches will be developed and validated against experimental data from the Engine Combustion Network. The simulations will be performed in a constant volume combustion vessel since it is a more effective crucible for model validation 3) Turbulence Modeling: Traditionally engine simulations have been performed using the Reynolds Average Navier Stokes Equations (RANS) approach. RANS employs filtering in time to derive the governing equations for the mean state. Turbulent interactions over the full range of dynamic scales are averaged to make the calculations affordable for engineering analysis. Only the largest energy containing features in a flow are resolved and no information exists to describe broadband small-scale interactions. Thus, computational requirements for RANS are relatively low and the most affordable. However, case-by-case calibration of models is required, and stochastic processes such as cycle-to-cycle variations cannot be captured in RANS. Large Eddy Simulation (LES) directly resolves the large scale unsteady motions that account for the bulk spatial transportation, while smaller scales of the flow are removed through a filtering operation and treated by using subgrid scale (SGS) models f or reduced computational cost. By resolving the large-scale turbulence, LES can significantly improve the accuracy of flow predictions compared to RANS. A dynamic structure based LES model will be developed and the results will be compared against RANS. The CONVERGE software has been observed to scale well up to 256 processors and full-cycle engine simulations. Current: undetermined amount Justification: Requested: 150000 A specific reason has been given: Preparing for an SAE paper and several of our large cases have crashed without yielding meaningful results. Additional core hours will ensure that we will be able to submit this SAE paper. 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 29 Jul '14

29 Jul '14

Hello, A change in allocation has been requested: Requester: ssom (Sibendu Som) Project: cavitation-modeling Title: Development of cavitation models for compression ignition engines Description: This research activity will mainly focus on comparing the cavitation models existing in the state-of-the-art engine modeling codes CONVERGE, OpenFOAM, and AVL-FIRE. Most cavitation models assume that vapor formation is initiated by the presence of cavitation nuclei which grow to become bubbles and then to form the complex structures also observed experimentally. The transport of vapor can be modeled either as discrete vapor bubbles or as a continuum. The Lagrangian tracked approach can handle natively different velocities for bubbles and liquid by solving the Newton law expressing the balance of forces acting on them. Among Eulerian methods, the multi-fluid model (implemented in AVL-FIRE) is conceptually superior to the single-fluid model (implemented in CONVERGE), since the latter is a homogeneous method therefore only one velocity is shared by all phases; while in a multi-fluid model each phase has its own velocity since momentum is solved separately for each fluid. In this case proper source terms accounting for the exchange of momentum between the phases have to be accounted for. In addition to that, a number of other physical processes have to be simulated. The most important one is the mechanism leading to bubble growth/collapse, i.e. the mass exchange model in cavitating conditions. The so-called Rayleigh-Plesset equation forms the basis for this modeling. The complete non-linear form, even if it is numerically stiff to be integrated, can be implemented in a multi-fluid model. Cavitation threshold can be expressed in terms of saturation pressure if the flow is quasi-steady, or adding viscous shear stress effects for high viscous or high velocity flows. By introducing a plenum for the outlet chamber and using a three-fluid model consisting of liquid, vapor and air, the nozzle outlet region can be resolved. This avoids the setting of unphysical boundary conditions at the nozzle exit and it allows reproducing the flow field accurately even in the proximity of the outlet. In case of super-cavitation the vapor plume can extend slightly beyond the outlet ; in case of hydraulic flip air can re-enter the hole region. An advantage of this approach is that the nozzle flow analysis is coupled to the in-cylinder flow, which results in the possibility of consideration of in-cylinder pressure variations, recirculation in cavitating flows (hydraulic flip), etc. Specific deliverables: - Comparison between single-fluid model (CONVERGE) and multi-fluid (FIRE) models and validation against experimental x-ray radiography data from Argonne. - Perform transient simulations of ECN injectors and perform validation against ECN data - Compare CONVERGE and FIRE results against transient ECN data - Assessment of transient effects: Series of steady simulations at fixed lift vs. transient simulations. - True needle movement (by x-ray visualization, Argonne) vs. idealized needle movement with n-dodecane as diesel surrogate - Coupling with outlet chamber in steady and time varying pressures (combustion chamber conditions) Current: undetermined amount Justification: Requested: 150000 A specific reason has been given: Preparing for an SAE paper and several of our large cases have crashed without yielding meaningful results. Additional core hours will ensure that we will be able to submit this SAE paper. 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 29 Jul '14

29 Jul '14

Hello, A change in allocation has been requested: Requester: ssom (Sibendu Som) Project: LES-sprays Title: LES modeling for diesel spray and engine simulations Description: The project is divided into four major tasks to be performed in 3 years in collaboration with Convergent Science Inc., and Cummins Engine Company: Task 1: 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 for non-evaporating and evaporating diesel sprays. Different flavors of LES models such as dynamic structure and Smagorinsky will be compared against RANS approach and without any sub-grid scale (SGS) model. Task 2: This task will focus on extending the LES spray modeling approach for performing combustion simulations. Grid-convergence of LES combustion simulations will be assessed and recommendations will be provided minimum grid-sizes keeping in mind run-time vs. accuracy for LES modelers. Task 3: The above tasks will benchmark LES approach for full-cycle engine simulations. The recommended minimum cell sizes will be implemented for performing engine simulations. Cycle-to-cycle variations will be captured using the LES approach. Validation of the engine simulations will be performed against experimental data available in literature. Task 4: Since LES requires small resolutions the wall-clock times for the above tasks will be large. In general, such high wall-clock times are not affordable in the industry. The last task will be focus on further improving the SGS models to obtain flow structures even at coarser resolutions. The specific methods used for the multi-phase, reacting flow simulations with moving boundaries will include: 1) Finite volume schemes 2) LES (dynamic structure) and RANS turbulence models used 3) Detailed chemical kinetic models for diesel fuels 4) CONVERGE software is being used - ~128 licenses available 5) Scales well up-to 128 processors 6) Detailed spray models used for different spray processes Current: undetermined amount Justification: Requested: 150000 A specific reason has been given: Preparing for an SAE paper and several of our large cases have crashed without yielding meaningful results. Additional core hours will ensure that we will be able to submit this SAE paper. 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 23 Jul '14

23 Jul '14

Hello, A change in allocation has been requested: Requester: mgrippo (Mark Grippo) Project: MHK Title: Hydrodynamic model development for Cobscook Bay Description: Create high resolution hydrodynamic model for Cobscook Bay Maine Current: undetermined amount Justification: Our run (with turbines activated) simulated 6 days of tides in 12 days of computer time, i.e., 12 real time days. That comes to 12 days * 24 hours * 360 cores = 103680 core-hours for a 6 day tidal simulation. This is for our marconi cluster at UMaine. The rate is 130680 core.hours / (6 days*24 hours*360 cores) = 2 core-hours per 1 hour of tides simulated per core. For the Fusion cluster, we have 800 nodes at roughly the same cpu speed and available memory. So, the rate is 103680 core.hours /( 6 days*24 hours*800 cores ) = 0.9 core-hour per 1 hour of tides simulated per core. We expect to do 7 simulations. 5 simulations of experiments (each is 7 days long) 2 simulation of calibration (each is 14 days long) This gives (5 runs * 7 days) +( 2 runs *14 days) = 63 days of tidal simulations = 1512 hours of tidal simulations. That translates to: 0.9 core-hour per 1 hour of tidal simulated per core * 1512 hours of tidal simulation = 1361 core-hours per core. That comes to 1361 core-hours per core *800 cores=1,088,640 core hours. Requested: 342000 A specific reason has been given: We estimate that 2 additional runs are needed for the validation of the model (estimated at 193k core-hours per run). This comes to 387k core-hours. At this point we only have 45k usable core-hours left from our previous allocation. Thus we need an additional 342k core-hours (387-45) to finish our work. 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] Fwd: [LCRC alloc-com] LCRC additional allocation request for project MHK
by John Valdes 23 Jul '14

23 Jul '14

Resubmitting this request via the web on behalf of Mark (so when you see it, you can ignore it, as it's just me) and then granting the hours. John On Mon, Jul 21, 2014 at 06:46:08PM +0000, Bair, Raymond A. wrote: > We have 5 yes votes so far, which is a majority > > Ray > > Sent from my iPhone > > Begin forwarded message: > > From: "Bair, Raymond A." <rbair(a)anl.gov<mailto:[email protected]>> > Date: July 21, 2014 at 9:30:33 AM CDT > To: "alloc-com(a)lcrc.anl.gov<mailto:[email protected]>" <alloc-com(a)lcrc.anl.gov<mailto:[email protected]>> > Cc: LCRC Core <lcrc-core(a)lcrc.anl.gov<mailto:[email protected]>> > Subject: [LCRC alloc-com] LCRC additional allocation request for project MHK > > Dear LCRC Allocations Committee, > > Attached is a justification requesting addition of 342K core-hours to > project MHK in this quarter: PI Mark Grippo (EVS). To date MHK has been > allocated 740K hours and has 32K remaining. > > Please let me know if you approve the request, by 7/23 (Wednesday). > > Best regards, > > Ray > > ----------------------------------------- > Ray Bair > Computing, Environment, and Life Sciences > Argonne National Laboratory > and the University of Chicago > TCS Building 240, Room 4122 > 9700 South Cass Avenue > Argonne, IL 60439 > email: rbair(at)anl.gov<http://anl.gov> > Phone: (630)252-5751 > > <LCRC Justification mg.docx> > _______________________________________________ > alloc-com mailing list > alloc-com(a)lists.lcrc.anl.gov<mailto:[email protected]> > https://lists.lcrc.anl.gov/mailman/listinfo/alloc-com > _______________________________________________ > allocations-admins mailing list > allocations-admins(a)lcrc.anl.gov > https://lists.lcrc.anl.gov/mailman/listinfo/allocations-admins

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