Mapping of Airflow Patterns in Engines with Induction Swirl

The induction process in a stratified engine using swirl was successfully studied by means of an analogous water model using neutral density beads. The studies revealed that the swirl generated by a masked intake valve is characterized by solid body rotation near the center and potential flow in the outer portions. The vortex is unstable and nonsymmetrical with its center of rotation offset from the cylinder axis and forming a helix extending the length of the cylinder.