Geometric parameters influencing flow in an axisymmetric IC engine inlet port assembly: Part I - Valve flow characteristics

Discharge characteristics in an IC engine inlet port and the dependency on geometrical parameters are examined for two valves having seat angles of 40 and 45 deg. The characteristics were established under steady-state condit ions over a range of valve lifts up to L/D =0.25 and pressure differentials up to 100 mm H2O. The detailed boundary layer characteristics, indicating flow separation and reattachment on the valve sears, were established with the aid of hear transfer data using the transient liquid crystal technique. Details of the experimental methods for obtaining discharge coefficients a nd heat transfer coefficients are presented The discharge and heat transfer data established the expected sequential progression. with lift through th e four flow regimes for the valve with a 45 deg seat angle. For the valve w ith a 40 deg seat angle the four flow regimes were not present. The results demonstrate the extreme sensitivity of the valve flow and boundary layer s tate to small changes in valve geometry.