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A new computer code, AGNI-3D, has been developed for the modeling of combustion, spray, and flow properties in a stratified-charge rotary engine (SCRE). The mathematical and numerical details of the new code are described by the first author in a separate NASA publication. The solution procedure is based on an Eulerian-Lagrangian approach where the unsteady, three-dimensional Navier-Stokes equations for a perfect gas-mixture with variable properties are solved in generalized, Eulerian coordinates on a moving grid by making use of an implicit finite-volume, Steger-Warming flux vector splitting scheme. The liquid-phase equations are solved in Lagrangian coordinates. The engine configuration studied was similar to existing rotary engine flow-visualization and hot-firing test rigs. The results of limited test cases indicate a good degree of qualitative agreement between the predicted and measured pressures.

A computer program -- LeRC3D.Wankel -- was developed to study the flow, spray, and spray combustion in the combustion chambers of Wankel rotary engines. LeRC3D. Wankel is based on an Eulerian-Lagrangian formulation. The gas phase was modelled by an Eulerian approach using the density-weighted, ensemble-averaged conservation equations of mass, momentum (full compressible Navier-Stokes), total energy, and species, closed by a low Reynolds number k-ε turbulence model. The liquid phase, made up of fuel droplets, was modelled by using a Lagrangian approach in which droplet groups are tracked in time. The combustion process which takes place after fuel droplets evaporate and mix with the surrounding air was assumed to be chemical kinetics controlled via a two-step global mechanism. This paper describes the formulation employed in the computer program as well as the essence of the numerical method used to generate solutions. Some computed solutions for the flow field are also presented.