Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Sibendu Som Project Name: LES-Engine Division: ES Project title: Computation Fluid Dynamics Modeling of Diesel Injectors and Fuel Sprays under Transient Operating Conditions Associated funding: DOE Office of Vehicle technologies Other Systems: University of Perugia Science: This project will use a Computation Fluid Dynamics (CFD) software called CONVERGE to model transient two phase flows in fuel injectors and combustion chambers using highly resolved Large Eddy Simulations (LES) in an Eulerian approach. The idea is to investigate high pressure fuel injectors, where needle opening and closing transients cause complex off-design fluid dynamics behaviors that profoundly impact the mixture formation processes and affect emission and combustion performance of engines. A new gas dissolution model is under development which will be integrated in the CFD code and will extend the prediction capability of the model. The simulation results and methodology developed in this projects will pave the way for novel and more efficient fuel injector design methods, for either gasoline or diesel engines. Project description: The project will be divided in the following parts. Initially, injection transients for single hole injectors will be simulated, without dissolution model. We will be studying the grid requirements, initialization of internal domain with liquid or liquid-gas mixture, effects of injection pressure and back-pressure. These simulations will run on about 64-256 cores, for few days. In a parallel stage, we will be testing the dissolution gas model on fuel injectors and other flow test devices. These simulations will require 64-128 cores for few days. Results will be compared against available experimental data collected at the APS. Once the correct setup of the time scale involved in the mass transfer process of cavitation and gas absorption/dissolution have been assessed, this information will be retained for the subsequent steps. Next, opening and closing injection transients will be simulated introducing the advancements derived from the dissolved gas mode l. Single and multi-hole injectors will be simulated in this last main part of the project at full resolution, and with the optimal multiphase flow code setup. These selected simulations will run on about 128-256 cores, for about two weeks each. Industry partnership: Convergent Science Project URL: http://www.transportation.anl.gov/engines/multi_dim_model_home.html Current FY Hours Used: undetermined amount New FY Requested allocation: 600000 Q1: 150000 Q2: 150000 Q3: 150000 Q4: 150000 Justification: Our recent publication (J. Kodavasal, K. Harms, P. Srivastava, S. Som, S. Quan, K.J. Richards, M. Garcia, “Development of stiffness-based chemistry load balancing scheme, and optimization of I/O and communication, to enable massively parallel high-fidelity internal combustion engine simulations,” Journal of Energy Resource Technology; JERT-16-1022, 2016) together with MCS and Convergent Science discusses the improvements to the Converge tool that has resulted in significant improvement in scaling. Currently, we are able to scale the code up to 4096 processors on Mira with about 70% scaling efficiency for a fixed mesh size. This was achieved due to the implementation of: (1) MPI I/O, (2) Improved Communication, (3) METIS load balancing scheme, (4) Development of a new chemistry load balancing scheme. Storage requirements: 5 TB Thank You, The LCRC Accounts System