Measurement of Valve Flows of a Four-valve S. I. Engine as Boundary Conditions for In-Cylinder Flow Models

The three velocity components and turbulence intensity were measured at the valve curtains around the two inlet valves of a four-valve s.i. engine with a pent-roof chamber. The measurements were made using hotwire anemometry in a steady-flow rig. Data were collected over a wide range of valve lifts and flow rates.

The results show that the velocity profiles are strongly dependent on the valve lift and the surrounding geometry but almost insensitive to the flow rate. Flow separations are identified at certain azimuthal locations for large valve lifts. The turbulence intensity varies around the valve peripheries and across the valve gaps, as do the exit angles of the issuing flows. Their profiles are affected by flow separations from the valve seats and faces and by flow interferences between the two inlet valves. These detailed profiles can be used as boundary for multi-dimensional in-cylinder flow models.