Flowbench Calibration of a Numerical Model for a Novel Uniflow-Scavenged Two-Stroke GDI Engine 2006-01-3268

The development of a uniflow-scavenged two-stroke engine is in progress at Queen's University, Canada. This novel engine has a unique cylinder head design that contains an array of check valves to control the airflow into the cylinder. Since the intake airflow is of great importance to engine performance, a detailed investigation is required. A numerical model created with Fluent 6.2 was used to simulate the airflow through the cylinder head in the effort to understand the flow and ultimately improve the head design. At the same time a flowbench test was performed to obtain steady flow data used to calculate a flow coefficient associated with the airflow through the cylinder head. The experimental flowbench data also provides a useful tool to validate the numerical model. Thus, this paper presents the development and verification of a numerical model that simulates airflow through the cylinder head. Mass flow rates and flow coefficients derived both experimentally and by simulation are presented. The numerical model predicts the flow coefficient to within approximately 10%. Discrepancies may exist due to the improper prediction of the spreading rate of the jets which influences the interaction of the jets with each other and the confining wall.