Hello,
A change in allocation has been requested:
Requester: ssom (Sibendu Som)
Project: LES-sprays
Title: LES modeling for diesel spray and engine simulations
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 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
Current: undetermined amount
Justification:
Requested: 77000
A specific reason has been given:
We have been running several multi-cycle LES calculations which are extremely expensive
This needs to be approved and the final allocation amount decided upon.
Thank You,
The LCRC Accounts System
