Abstract
A numerical model for hyperbolic combustion within a four-stroke heat-barrier piston engine has been developed. An idealized fuel injector simulates the type of injector used in current experimental hypergolic combustion research. Significant to the modeling of this injector is the need to overcome the problems posed by a unit Mach number boundary condition at the injector orifice opening. Overall, the model is used to simulate a compression stroke and fuel injection portion of a power stroke. An implicit finite-difference solution of the governing flow field equations is used. The engine is modeled with the fuel injector being colocated with a single valve, making possible an axisymmetric solution. Because of its physics, hypergolic combustion dictates an eddy dissipation combustion approach. In the final run a 20 × 26 mesh is used for the greater region, which is made up of the flow field and a thin portion of the adjacent cylinder linings and piston.