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: GasTurbineCombustion Project title: Benchmark Combustion Simulations for Gas Turbine Applications Associated funding: Other Systems: Convergent Science Inc. Science: The "entitlement rig" is commonly used to benchmark combustion simulations for gas turbine applications. Steady state simulations are typically run with a Reynolds Averaged Navier Stokes (RANS) based turbulence model. At lower equivalence ratios, the combustion is known to be unstable. Thus, a RANS based turbulence model may not be appropriate for these conditions. An advantage of RANS based turbulence model is that they can be run with coarser mesh resolutions. However, to properly capture the combustion performance at lower equivalence ratios, it may be best to use a Large Eddy Simulation (LES) turbulence to simulate the unsteady combustion behavior. Project description: With the use of parallel processing and highly-scalable CFD solvers, LES is becoming an increasingly practical technique for modeling the turbulent flow in internal combustion engines. Recently it has been shown by Argonne and CSI 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. Grid-convergence behavior of a dynamic structure based LES model was demonstrated by employing minimum cell sizes in the order of 30 microns under evaporating but non-combustion spray conditions. This methodology has not yet been applied to the simulation of a gas turbine combustion using the CONVERGE code. We propose to run the combustion simulations at a lower equivalence ratio with an LES turbulence model. Using the LES model should capture the unsteady combustion behavior. A disadvantage of LES turbulence model is that the simulations typically require more grid resolution than a RANS simulation. Comparisons on emissions (CO, CO2, NOx) will be performed between RANS and LES simulations. Demonstration of grid-convergence in a real engine simulation is challenging due the need to resolve finer flow structures across larger volumes which may result in high computational costs. This project will address these challenges by using advanced load-balancing algorithms (such as METIS), reduced chemical kinetic models for combustion (ensuring that the fidelity of the model is very high under the operating conditions), multi-zone model, HPC resources to ensure lower wall-clock times, adaptive mesh resolution technique to add cells in desired locations of high temperature, species, and velocity gradients, and sector simulations for bench-marking the LES. The key will be to develop “best practices” for LES gas turbine combustion simulations. 1) Finite volume schemes 2) LES (dynamic structure) and RANS turbulence models used 3) Detailed chemical kinetic models for gas turbine fuels 4) CONVERGE software is being used - ~128 licenses available 5) Scales well up-to 128 processors Project URL: Requested allocation: 499000 Q1: 0 Q2: 0 Q3: 150000 Q4: 349000 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