Fuel Spray Modeling

High-fidelity Large Eddy Simulations

Convergent Science Inc. (CSI) has licensed a combustion chemistry code — the Multi-Zone Chemistry Solver — for designing engines from Lawrence Livermore National Laboratory (LLNL).

The Multi-Zone Chemistry Solver is an added-value capability of CSI’s industry leading engine computational fluid dynamics (CFD) software, CONVERGE.

Utilizing CSI’s computational fluid dynamics software with LLNL’s efficient detailed chemical kinetics approach provides a powerful tool for design optimization of combustion processes in piston engines, including compression ignition engines (Diesel), spark ignition (gasoline) and for development of advanced engine combustion concepts, such as Homogeneous/Premixed Charge Compression Ignition (HCCI/PCCI), Low Temperature Combustion, and other High Efficiency Clean Combustion (HECC) approaches.

The multi-zone chemistry solver computes finite rate chemistry phenomena in a scalar state-space, as opposed to the physical space in which the fluid mechanics is solved. This approach allows for aggregating the solution of not-necessarily-connected regions of the geometry that undergo similar scalar-state history (e.g., temperature-equivalence ratio history).

The multi-zone approach has inherent efficiencies and is further enhanced with parallelization of the chemical zone calculations in conjunction with the message-passing-interface (MPI) library, as well as implementation of highly efficient numerics for kinetic reactor solution.

The integration of the multi-zone solver will allow CONVERGE users to perform engine CFD simulations considering detailed chemistry with drastically reduced computational requirements. Therefore, CONVERGE users will benefit from shorter run times and the ability to utilize larger chemical mechanisms to accurately predict phenomena such as knock, HCCI and flame propagation.

“We are thrilled to work with major R&D facilities like LLNL to leverage their world class expertise in multi-zone chemistry technologies. Significantly speeding up the chemistry, in addition to standard CONVERGE features such as the elimination of all user meshing time and adaptive mesh refinement, will assure that CONVERGE remains the code of choice for engine CFD analysis,” states Dr. Daniel Lee, director of business development at Convergent Science Inc.

Dr. Daniel Flowers, associate program leader for Combustion and Alternative Fuels at LLNL, observes, “We use CSI’s parallel fluid mechanics capabilities, combined with LLNL’s efficient computational chemistry, to give us the ability to conduct high-fidelity simulations of engine combustion that resolve flow in complex geometries and include the large detailed chemical kinetic mechanisms needed for practical hydrocarbon fuels.”

For more information, please follow the links below:

Convergent Science, Inc.:

www.convergecfd.com

LLNL:

www.llnl.gov