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: Sibendu Som Applicant's institution: ANL Applicant's division: Energy Systems Project Name: LES-sprays Project title: LES modeling for diesel spray and engine simulations Associated funding: DOE - Office of Vehicle Technologies Other Systems: Convergent Science Inc., Cummins Engine Company Science: With the use of parallel processing and highly-scalable CFD solvers, Large Eddy Simulation (LES) is becoming an increasingly practical technique for modeling the turbulent flow in internal combustion engines. Recently we have shown that LES can provide good qualitative and quantitative comparisons to instantaneous engine spray measurements since it directly resolves the large scales in the flow field. While LES can offer higher fidelity solutions compared to the more traditional Reynolds-Averaged Navier-Stokes (RANS) methods, a grid-convergent implementation is necessary to have confidence that the important flow structures are adequately resolved. LES also offers potential to capture “cycle-to-cycle” variations which are generally damped out in a RANS approach. “Cycle-to-cycle” variations are commonly observed in both diesel and spark ignited engines. The proposed objectives of this project are aimed at further enabling the predictive simula tions of internal combustion engines using high-fidelity LES models. The LES turbulence model developments will be performed using the commercial code called CONVERGE in collaboration with the developers of the code. This tool is being used by several transportation OEMs such as Caterpillar Inc., Chrysler LLC., Cummins Inc., Ford Motor Company, etc. Hence, these developments in LES turbulence modeling will readily facilitate predictive simulations of the internal combustion engines. Project 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 multiphase, 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 - ~500 licenses available 5) Scales well up-to 128 processors 6) Detailed spray models used for different spray processes Project URL: http://www.transportation.anl.gov/engines/multi_dim_model_home.html Requested allocation: 497000 Q1: 0 Q2: 77000 Q3: 210000 Q4: 210000 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