Investigation of the Effect of Inlet Port on the Flow in a Combustion Chamber Using Multidimensional Modeling

Abstract

The computational fluid dynamics simulation program KIVA is augmented with a k-ε turbulence model and enhanced geometric capabilities. It is applied to the case of flow in an inlet port and a combustion chamber with a moving valve in order to investigate the effect of inlet flow on the prevailing aerodynamic conditions in the cylinder. The needed initial and time-varying boundary conditions at the upstream section of the intake port are obtained from a one-dimensional acoustic model of the complete single cylinder engine. The three-dimensional flow domain includes an intake port, a combustion chamber, and a moving valve. An internal dynamic rezoning procedure is presented and incorporated in the flow code, which ensures an adequate I, J, K-structured hexahedral mesh when the boundaries of the computation domain are severely distorted, as is the case with a moving valve. Flow computation is carried out from induction TDC to BDC. The resulting velocity and residual burned gas mass fraction fields are then examined and effects due to the geometry of the port and chamber are discussed.