February 2017 - Allocations-admins - mailman3.cels.anl.gov

Re: [allocations-admins] [LCRC Accounts] Project Allocation Request
by Roberts, John E. 03 Feb '17

03 Feb '17

Yes, done in December. -- John Roberts Argonne National Laboratory CELS Systems jeroberts(a)anl.gov On 1/31/17, 1:15 PM, "allocations-admins-bounces(a)lcrc.anl.gov on behalf of Bair, Raymond A." <allocations-admins-bounces(a)lcrc.anl.gov on behalf of rbair(a)anl.gov> wrote: Has this change been made? ----------------------------------------- Ray Bair Argonne National Laboratory and the University of Chicago On 12/8/16, 1:27 PM, "allocations-admins-bounces(a)lcrc.anl.gov on behalf of Bair, Raymond A." <allocations-admins-bounces(a)lcrc.anl.gov on behalf of rbair(a)anl.gov> wrote: Recommend that we approve 150K. ----------------------------------------- Ray Bair Argonne National Laboratory On 12/6/16, 10:51 PM, "allocations-admins-bounces(a)lcrc.anl.gov on behalf of accounts(a)lcrc.anl.gov" <allocations-admins-bounces(a)lcrc.anl.gov on behalf of accounts(a)lcrc.anl.gov> wrote: Hello, A change in allocation has been requested: Requester: ssom (Sibendu Som) Project: gm_gasexchange Title: Modeling Cyclic Variability in the GM TCC Engine Using LES 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 fired GM transparent combustion chamber (TCC) engine with a base grid size of 0.5 mm. Adaptive mesh refinement will be employed to resolve the flame region with a 0.125 mm grid. The mean and variance of the predicted flow field and the in-cylinder pressures will be compared to the PIV measurements. In the second part of this study, the parallel cycle methodology will be extended to the fired TCC engine, which will enable fast throughput computation of the cyclic variability. In the previous year, this methodology was demonstrated for motored conditions. In the final part of this study, the parallel cycle methodology will be used to perform a parametric study on the influence of numerical parameters like minimum grid size, number of cycles, and spark energy deposition on the predicted cyclic variability. Current: undetermined amount Justification: Requested: 150000 A specific reason has been given: we ran more simulations than what we were expecting to run initially. These extra simulations have resulted in an additional paper with GM R&D for SAE WC 2017. 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)lcrc.anl.gov https://lists.lcrc.anl.gov/mailman/listinfo/allocations-admins _______________________________________________ allocations-admins mailing list allocations-admins(a)lcrc.anl.gov https://lists.lcrc.anl.gov/mailman/listinfo/allocations-admins _______________________________________________ allocations-admins mailing list allocations-admins(a)lcrc.anl.gov https://lists.lcrc.anl.gov/mailman/listinfo/allocations-admins

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Re: [allocations-admins] [LCRC Accounts] Project Allocation Request
by Bair, Raymond A. 02 Feb '17

02 Feb '17

This looks like a reasonable request for 150K. Scale by the usual scale factor? P.S. Previously 100K was added in December. ----------------------------------------- Ray Bair Argonne National Laboratory and the University of Chicago On 2/1/17, 5:03 PM, "allocations-admins-bounces(a)lcrc.anl.gov on behalf of accounts(a)lcrc.anl.gov" <allocations-admins-bounces(a)lcrc.anl.gov on behalf of accounts(a)lcrc.anl.gov> wrote: Hello, A change in allocation has been requested: Requester: barlo (Lorenzo Bartolucci) Project: GAS_injection Title: High-Pressure Gaseous Fuel Injection Research – in-nozzle flow and jet evolution Description: This project focuses on investigating the in-nozzle flow for a gaseous inward opening injector and the consequently under-expanded jet evolution. This is aimed to provide a better comprehension of the local phenomenon and how those affect the typical behavior of the under-expanded gaseous jet (such as mach disk location and width, local thermo-fluid-dynamics properties and mixing with the surrounding mixture). At the current stage, the mesh influence on the quality of the numerical results has been deeply analyzed. An optimum mesh strategy and size have been found as a compromise between the numerical accuracy and the computational costs. The x-ray radiography data has been used as a reference for the comparison. Preliminary results have been obtained for the steady state simulation showing a good agreement with the experimental data. Currently an improvement in the agreement in terms of jet spread and mass distribution is under investigation. Future work would aim to represent also the opening and closing transient to provide a detailed instrument of analysis of the high injection phenomena occurring during these unsteady phases. Simulations will be performed with the commercial code CONVERGE and computational grids of the order of 15 millions of cells which will require the use of 64-144 cores depending on the specific case. The project has one member (barlo) working full-time on it, with 1-2 cases running regularly. With an average estimate of 96cores per run and 2 cases the expected amount of core-hrs needed for this project for each quarter is 96 cores x 24 hrs x 2 runs x 90 days = 414720. Considering some queue and post-processing time our request is for 1000000 hrs total, equally distributed for each quarter. Current: undetermined amount Justification: Recent scalability test (June 2016) performed on Blues provided following results: Simulation of gas jet from inward opening pintle. Mesh size = 15,000,000 cells 1 node (16 cores) – walltime = memory problems 2 nodes (32 cores) – walltime = 45min 15sec à 100 % 3 nodes (48 cores) – walltime = 33min 18sec à 90 % 6 nodes (96 cores) – walltime = 21min 50sec à 70 % Requested: 150000 A specific reason has been given: Since the high computational resources needed for the detailed simulation of the gaseous injection I would ask for an extention of the corehours dedicated to the project in order to finalize the paper carrying out the latest simulations with high computation grid resolution. 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 Bair, Raymond A. 02 Feb '17

02 Feb '17

This request is for Q3 and Q4. ----------------------------------------- Ray Bair Argonne National Laboratory and the University of Chicago On 2/1/17, 4:36 PM, "allocations-admins-bounces(a)lcrc.anl.gov on behalf of accounts(a)lcrc.anl.gov" <allocations-admins-bounces(a)lcrc.anl.gov on behalf of accounts(a)lcrc.anl.gov> wrote: Hello, A change in allocation has been requested: Requester: linyun (Linyun Liang) Project: Meso_Nuclear Title: Gas bubble kinetics in an irradiated U-Mo using a mesoscale simulation approach Description: A mesoscale simulation approach is developed to study the gas bubble evolution kinetics in irradiated U-Mo alloy fuels. Density functional theory is first utilized to predict the defect formation energies, the Xe-U-Mo interfacial energy, and the elastic constants of U-Mo alloys, among other quantities. These obtained material properties are then incorporated into a mesoscale model to study the kinetics of gas bubbles in U-Mo under irradiation. By developing a new free energy model of Xe gas bubble based on the van der Walls equation of state, the gas bubble pressure can be estimated. The effects of vacancy and self-interstitial atom (SIA) diffusion on the gas bubble pressure will be further investigated and validated. The events employed in the simulation are the absorption and emission of a vacancy, a SIA, and an interstitial U by a single Xe bubble, while an event associated with SIA loops or substitutional U is neglected here for simplicity. We will systemat ically investigate the effect of Xe, vacancy, and SIA concentration, fission defect generation and their recombination, sink strength, grain boundaries, and elastic interaction on the growth kinetics of gas bubble. The swelling of U-Mo due to fission gas bubble will be simulated and compared to experimental observations. Our study aims to provide insight into understanding of the structural damage in irradiated U-Mo materials. In our phase field model, we have four highly non-linear, coupled partial differential equations which must be solved numerically. In the meaning time, the elastic equilibrium equation is also included in each time step, which requires to obtain the elastic solution at the equilibrium state for each time step and can significantly increase the cost of the simulation time. And also in order to avoid the partial loss of interfacial energy, we will extend our model to three dimensional system. Therefore, to effectively solve this problem, we will need about 150,000 core hours including the 6,000 core-hour to debug and test the algorithm and code and 144,000 core-hours (4 cores/node * 4 nodes * 10 hours of run time * 800 different runs) for the nucleation and growth of gas bubbles calculations. We will use our developed FFTW code to solve the problem. By using the Fusion and Blues computing resources will greatly accelerated the code development and calculations. In conclusion, the total core-hours requested for this project throughout the FY2016 will be 150,000 core-hours. Fig. 1 Simulated results of gas bubbles nucleation and growth under the irradiated U-7Mo. Current: undetermined amount Justification: Requested: 150000 A specific reason has been given: I have zero allocation core-hours. I am requesting more core-hours as below. Quarter 3 requests 50000 core-hours. Quarter 4 requests 100000 core-hours. 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)lcrc.anl.gov https://lists.lcrc.anl.gov/mailman/listinfo/allocations-admins

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Re: [allocations-admins] Project Allocation Request - ESMF
by Bair, Raymond A. 02 Feb '17

02 Feb '17

Thank you, Silverio. 50K makes sense. Regards, Ray ----------------------------------------- Ray Bair Argonne National Laboratory and the University of Chicago From: Silverio Vasquez - NOAA Affiliate <silverio.vasquez(a)noaa.gov> Date: Wednesday, February 1, 2017 at 2:24 PM To: Raymond Bair <rbair(a)anl.gov> Cc: "svasquez(a)lcrc.anl.gov" <svasquez(a)lcrc.anl.gov>, Rob Jacob <jacob(a)mcs.anl.gov>, Cecelia DeLuca - NOAA Affiliate <cecelia.deluca(a)noaa.gov> Subject: Re: [allocations-admins] Project Allocation Request - ESMF Ray, It was a mistake, I did not intend to request 350,000 core-hours. I think the form defaulted to that amount. I would like to request 50,000 core-hours. Let me know, if that is acceptable. Thanks, --Silverio On Tue, Jan 31, 2017 at 12:25 PM, Bair, Raymond A. <rbair(a)anl.gov<mailto:[email protected]>> wrote: Resending, in case the last note was lost. ----------------------------------------- Ray Bair Argonne National Laboratory and the University of Chicago On 1/24/17, 11:42 AM, "allocations-admins-bounces(a)lcrc.anl.gov<mailto:[email protected]> on behalf of Bair, Raymond A." <allocations-admins-bounces(a)lcrc.anl.gov<mailto:[email protected]> on behalf of rbair(a)anl.gov<mailto:[email protected]>> wrote: Dear Silverio Vasquez [and Rob Jacob], The current ESMF project allocation is 12,000 core-hours for FY2017. So far, 34,000 core-hours have been used. Requesting more time is fine; however, more information is needed. You say that the tests are running longer than expected. However, going from 34,000 to 350,000 core-hours is quite a jump. Can you show us how this estimate was made, e.g., core-hours for a run, times the number of runs needed? Regards, Ray ----------------------------------------- Ray Bair Argonne National Laboratory On 1/23/17, 12:51 PM, "allocations-admins-bounces(a)lcrc.anl.gov<mailto:[email protected]> on behalf of accounts(a)lcrc.anl.gov<mailto:[email protected]>" <allocations-admins-bounces(a)lcrc.anl.gov<mailto:[email protected]> on behalf of accounts(a)lcrc.anl.gov<mailto:[email protected]>> wrote: Hello, A change in allocation has been requested: Requester: svasquez (Silverio Vasquez) Project: ESMF Title: Earth System Modeling Framework Description: The previously released NUOPC Layer reference API was refined to provide a more object-oriented interface that better reflects the NUOPC Driver, Model, Connector, and Mediator concepts. The NUOPC Driver now allows child components to be added dynamically, supporting the implementation of more flexible applications. String labels are consistently used to identify component instances and initialize/run/finalize phases. The introduction of namespaces allows for more control over automatic field pairing, and LocStreams (a geometric type that can be used to represent a set of disconnected points) can now be transferred between components during initialize. The compliance checker has become aware of the component context and produces more useful output. Finally, some of the utility routines previously contained in the NUOPC Layer have moved into ESMF. In the area of ESMF regridding, a new application, ESMF_Regrid, was added. This command-line tool can be used to regrid a data field defined in a UGRID or GRIDSPEC format file to another field defined in a different file. The ESMF_RegridWeightGen application, which precomputes regridding weights, now supports additional options to i) allow non-conservative regridding on cell center locations in the unstructured case, ii) ignore degenerate cells, and iii) choose between different line options when regridding on a sphere. The ESMF regridding implementation now supports an option for using a first order conservative method for unstructured Meshes built on DOE's MOAB mesh library (the version built on ESMF's native mesh library is still available). ESMF unstructured Meshes have been extended to handle elements that consist of more than one polygon to allow the representation of geographically disconnected areas (e.g. the Hawaiian Islands) as a single element. The ESMF regridding capability was further extended to cover i) ESMF LocStreams, ii) first-order conservative regridding of concave quadrilateral cells, iii) non conservative regridding on Mesh elements with more than four sides, and iv) the use of great circle lines when computing 3D bilinear interpolation weights on a sphere. The ESMF Python interface ESMPy has matured and offers more complete coverage of the ESMF Grid, Mesh, and LocStream classes. It also now offers read methods that allow a Field to be filled with data from a NetCDF file. Anaconda packages are now available for easy installation of ESMPy on Linux and Darwin systems. Currently ESMF is regression tested daily on Blues with: -- gfortran with mvapich2, and mpich3 -- intel with mvapich2 and mpich2 -- nag with mpich2, mpich3, and openmpi -- pgi with mvapich2 and mpich3 On the Blues gfortran, benchmark testing is included to detect any unexpected change in the performance of the software. ESMPy is also tested on Blues with mvapich2. ESMPy is the ESMF Python Regridding inteface. ESMPy testing includes building and installing ESMF with NetCDF, building python, running unit tests, examples and regridding from files tests. On Fusion, ESMF is regression tested with: -- g95 with mvapich2 -- gfortran with mvapich2 and mpich2 -- intel mvapich2 mpich2 . The regression test includes: - building the ESMF software and installing it, - building and testing 6 applications, - building and running system tests, examples and unit tests bundled with the software. The entire test suite is run with debug and optimized settings. In addition, two versions of ESMF are regression tested, the head of the development, and a branch based on the last public release where limited development has continued. Current: undetermined amount Justification: Requested: 350000 A specific reason has been given: The ESMF regression tests are running longer than anticipated. 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)lcrc.anl.gov<mailto:[email protected]> https://lists.lcrc.anl.gov/mailman/listinfo/allocations-admins _______________________________________________ allocations-admins mailing list allocations-admins(a)lcrc.anl.gov<mailto:[email protected]> https://lists.lcrc.anl.gov/mailman/listinfo/allocations-admins

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[LCRC Accounts] Project Allocation Request
by accounts＠lcrc.anl.gov 01 Feb '17

01 Feb '17

Hello, A change in allocation has been requested: Requester: barlo (Lorenzo Bartolucci) Project: GAS_injection Title: High-Pressure Gaseous Fuel Injection Research – in-nozzle flow and jet evolution Description: This project focuses on investigating the in-nozzle flow for a gaseous inward opening injector and the consequently under-expanded jet evolution. This is aimed to provide a better comprehension of the local phenomenon and how those affect the typical behavior of the under-expanded gaseous jet (such as mach disk location and width, local thermo-fluid-dynamics properties and mixing with the surrounding mixture). At the current stage, the mesh influence on the quality of the numerical results has been deeply analyzed. An optimum mesh strategy and size have been found as a compromise between the numerical accuracy and the computational costs. The x-ray radiography data has been used as a reference for the comparison. Preliminary results have been obtained for the steady state simulation showing a good agreement with the experimental data. Currently an improvement in the agreement in terms of jet spread and mass distribution is under investigation. Future work would aim to represent also the opening and closing transient to provide a detailed instrument of analysis of the high injection phenomena occurring during these unsteady phases. Simulations will be performed with the commercial code CONVERGE and computational grids of the order of 15 millions of cells which will require the use of 64-144 cores depending on the specific case. The project has one member (barlo) working full-time on it, with 1-2 cases running regularly. With an average estimate of 96cores per run and 2 cases the expected amount of core-hrs needed for this project for each quarter is 96 cores x 24 hrs x 2 runs x 90 days = 414720. Considering some queue and post-processing time our request is for 1000000 hrs total, equally distributed for each quarter. Current: undetermined amount Justification: Recent scalability test (June 2016) performed on Blues provided following results: Simulation of gas jet from inward opening pintle. Mesh size = 15,000,000 cells 1 node (16 cores) – walltime = memory problems 2 nodes (32 cores) – walltime = 45min 15sec  100 % 3 nodes (48 cores) – walltime = 33min 18sec  90 % 6 nodes (96 cores) – walltime = 21min 50sec  70 % Requested: 150000 A specific reason has been given: Since the high computational resources needed for the detailed simulation of the gaseous injection I would ask for an extention of the corehours dedicated to the project in order to finalize the paper carrying out the latest simulations with high computation grid resolution. 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 01 Feb '17

01 Feb '17

Hello, A change in allocation has been requested: Requester: linyun (Linyun Liang) Project: Meso_Nuclear Title: Gas bubble kinetics in an irradiated U-Mo using a mesoscale simulation approach Description: A mesoscale simulation approach is developed to study the gas bubble evolution kinetics in irradiated U-Mo alloy fuels. Density functional theory is first utilized to predict the defect formation energies, the Xe-U-Mo interfacial energy, and the elastic constants of U-Mo alloys, among other quantities. These obtained material properties are then incorporated into a mesoscale model to study the kinetics of gas bubbles in U-Mo under irradiation. By developing a new free energy model of Xe gas bubble based on the van der Walls equation of state, the gas bubble pressure can be estimated. The effects of vacancy and self-interstitial atom (SIA) diffusion on the gas bubble pressure will be further investigated and validated. The events employed in the simulation are the absorption and emission of a vacancy, a SIA, and an interstitial U by a single Xe bubble, while an event associated with SIA loops or substitutional U is neglected here for simplicity. We will systemat ically investigate the effect of Xe, vacancy, and SIA concentration, fission defect generation and their recombination, sink strength, grain boundaries, and elastic interaction on the growth kinetics of gas bubble. The swelling of U-Mo due to fission gas bubble will be simulated and compared to experimental observations. Our study aims to provide insight into understanding of the structural damage in irradiated U-Mo materials. In our phase field model, we have four highly non-linear, coupled partial differential equations which must be solved numerically. In the meaning time, the elastic equilibrium equation is also included in each time step, which requires to obtain the elastic solution at the equilibrium state for each time step and can significantly increase the cost of the simulation time. And also in order to avoid the partial loss of interfacial energy, we will extend our model to three dimensional system. Therefore, to effectively solve this problem, we will need about 150,000 core hours including the 6,000 core-hour to debug and test the algorithm and code and 144,000 core-hours (4 cores/node * 4 nodes * 10 hours of run time * 800 different runs) for the nucleation and growth of gas bubbles calculations. We will use our developed FFTW code to solve the problem. By using the Fusion and Blues computing resources will greatly accelerated the code development and calculations. In conclusion, the total core-hours requested for this project throughout the FY2016 will be 150,000 core-hours. Fig. 1 Simulated results of gas bubbles nucleation and growth under the irradiated U-7Mo. Current: undetermined amount Justification: Requested: 150000 A specific reason has been given: I have zero allocation core-hours. I am requesting more core-hours as below. Quarter 3 requests 50000 core-hours. Quarter 4 requests 100000 core-hours. 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] Project Allocation Request - CMFD-RANS
by Bair, Raymond A. 01 Feb '17

01 Feb '17

200K sounds good to me too. Ray ----------------------------------------- Ray Bair Argonne National Laboratory and the University of Chicago On 2/1/17, 12:26 PM, "Aithal, Shashikant M." <aithal(a)cels.anl.gov> wrote: Ray: We could grant 200K core-hours (we should at least apply the original scaling factor of 0.85) for the next 2 months. Shashi ________________________________________ From: Bair, Raymond A. Sent: Wednesday, February 01, 2017 12:17 PM To: Aithal, Shashikant M. Subject: FW: Project Allocation Request - CMFD-RANS Hi Shashi, How does this plan look to you? Ray ----------------------------------------- Ray Bair Argonne National Laboratory and the University of Chicago On 2/1/17, 9:59 AM, "Shaver, Dillon R." <dshaver(a)anl.gov> wrote: Ray, I am attaching the timing information from the last case study. You can see the breakdown in terms of wall time and CPU-hours for each run. I'm estimating the next case study to take approximately twice as many resources due to a 2x larger computational domain. Fortunately the code (Nek5000) scales very well. -Dillon -----Original Message----- From: Bair, Raymond A. Sent: Wednesday, February 01, 2017 7:48 AM To: Shaver, Dillon R. Cc: LCRC Allocations Admins Subject: Re: Project Allocation Request - CMFD-RANS Dear Dillan, How much additional time do you need between now and March 31? What were the parameters the time needed, e.g., length and cores for a run times number of runs required? Regards, Ray ----------------------------------------- Ray Bair Argonne National Laboratory and the University of Chicago On 1/31/17, 4:59 PM, "allocations-admins-bounces(a)lcrc.anl.gov on behalf of accounts(a)lcrc.anl.gov" <allocations-admins-bounces(a)lcrc.anl.gov on behalf of accounts(a)lcrc.anl.gov> wrote: Hello, A change in allocation has been requested: Requester: dshaver (Dillon Shaver) Project: CMFD-RANS Title: Development of Multiphase RANS turbulence models Description: RANS and uRANS turbulence models are necessary for the accurate CFD simulation of flows on large scales, such as nuclear reactor fuel rod bundles and full cores. The current state-of-the art for simulation of boiling flows utilizes the RANS framework. Recently, the k-omega turbulence model has been demonstrated with Nek using a homogeneous equilibrium model of multiphase flow (thanks significantly to LCRC support). The goals of this project will be to further extend that model to more sophisticated formulations of multiphase flow, specifically the two-fluid model available in Nek-2P. This will enable the further development and validation of multi-phase models with Nek and the subsequent simulation of large, complex problems of interest in both science and industry. Additionally support for the development of the k-omega model will include simulations of a twin-jet mixing facility to evluate the model performce in capturing the effects of buoyancy and free -shear layers on turbulence. Both of which can play a signficant role in multiphase flows. This project will use the CFD code Nek5000 and its branch, Nek2P. Written in a combination of Fortran and C, Nek has been demonstrated to be a highly scalable code using the MPI library. Nek5000 has a long history of use and development on the LCRC systems. Proposed simulations will include helical pipe heat exchangers, nuclear reactor subchannels, and the turbulent mixing of twin jets. Meshes for these problems range in size from <100K elements to >1M elements. The project is expected to have between 2-4 members. Current: undetermined amount Justification: Requested: 250000 A specific reason has been given: The required simulations became significantly larger than initially anticipated and the design space has increased. With the success of the two-fluid model in Nek-2P, it is now being used for some limited parametric testing on the helical pipe heat exchanger. 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)lcrc.anl.gov https://lists.lcrc.anl.gov/mailman/listinfo/allocations-admins

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Re: [allocations-admins] Project Allocation Request - CMFD-RANS
by Bair, Raymond A. 01 Feb '17

01 Feb '17

Dear Dillan, How much additional time do you need between now and March 31? What were the parameters the time needed, e.g., length and cores for a run times number of runs required? Regards, Ray ----------------------------------------- Ray Bair Argonne National Laboratory and the University of Chicago On 1/31/17, 4:59 PM, "allocations-admins-bounces(a)lcrc.anl.gov on behalf of accounts(a)lcrc.anl.gov" <allocations-admins-bounces(a)lcrc.anl.gov on behalf of accounts(a)lcrc.anl.gov> wrote: Hello, A change in allocation has been requested: Requester: dshaver (Dillon Shaver) Project: CMFD-RANS Title: Development of Multiphase RANS turbulence models Description: RANS and uRANS turbulence models are necessary for the accurate CFD simulation of flows on large scales, such as nuclear reactor fuel rod bundles and full cores. The current state-of-the art for simulation of boiling flows utilizes the RANS framework. Recently, the k-omega turbulence model has been demonstrated with Nek using a homogeneous equilibrium model of multiphase flow (thanks significantly to LCRC support). The goals of this project will be to further extend that model to more sophisticated formulations of multiphase flow, specifically the two-fluid model available in Nek-2P. This will enable the further development and validation of multi-phase models with Nek and the subsequent simulation of large, complex problems of interest in both science and industry. Additionally support for the development of the k-omega model will include simulations of a twin-jet mixing facility to evluate the model performce in capturing the effects of buoyancy and free -shear layers on turbulence. Both of which can play a signficant role in multiphase flows. This project will use the CFD code Nek5000 and its branch, Nek2P. Written in a combination of Fortran and C, Nek has been demonstrated to be a highly scalable code using the MPI library. Nek5000 has a long history of use and development on the LCRC systems. Proposed simulations will include helical pipe heat exchangers, nuclear reactor subchannels, and the turbulent mixing of twin jets. Meshes for these problems range in size from <100K elements to >1M elements. The project is expected to have between 2-4 members. Current: undetermined amount Justification: Requested: 250000 A specific reason has been given: The required simulations became significantly larger than initially anticipated and the design space has increased. With the success of the two-fluid model in Nek-2P, it is now being used for some limited parametric testing on the helical pipe heat exchanger. 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)lcrc.anl.gov https://lists.lcrc.anl.gov/mailman/listinfo/allocations-admins

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