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: ES Project Name: LES-Engine Project title: Effect of LES resolved spray coupled with reduced kinetics on engine performance Associated funding: Other Systems: Convergent Science Inc., General Electric Science: Developing a clean engine, for meeting regulatory emission norms, and an efficient engine, for providing customer value, have been the main objectives for an OEM like GE. These ever evolving challenges have resulted in the introduction of enabling technologies like High Pressure Common Rail (HPCR), Exhaust Gas Recirculation (EGR), Miller Cams etc. To simulate this complex combustion system, it is understood that using Large Eddy Simulation (LES) based turbulence models, detailed chemical kinetics and a more complete modeling approach to nozzle and spray would enhance our understanding. However, these hi-fidelity simulations are computationally expensive. A load-balancing algorithm (METIS) in conjunction with a High Performance Cluster (HPC) would significantly bring down the run times. Also, detailed chemistry timescales can be reduced by using the multi-zone model or reducing the mechanism to a reasonable size. The primary objective of this proposal is to demonstrate the capability of an advanced LES based modeling of reciprocating engine combustion v/s current URANs based technique. This should improve the predictive ability of emissions and performance and aid in better understanding of newer combustion technologies. The second objective is to keep the runtimes of simulations reasonable such that these simulations can be readily performed using the HPC at GE. 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 diesel engine. 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 simulations on GE hardware. Through this collaboration the following activities are planned; 1. Dynamic structure based LES turbulence model coupled with reduced kinetics to evaluate engine performance using a sector mesh. a. This coupling of LES turbulence models with reduced kinetics is being attempted for the first time. A sector mesh is planned for to keep run times less than a week. 2. Comparison of existing modeling capability against the advanced approaches highlighted above. If indeed these advanced modeling techniques coupled with supercomputing is beneficial for GE; then we need to assess the scalability and speed-up of CONVERGE code with GE-hardware as a continuing exercise. 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 Project URL: Requested allocation: 499000 Q1: 450000 Q2: 49000 Q3: 0 Q4: 0 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