Geometric parameters influencing flow in an axisymmetric IC engine inlet port assembly: Part II - Parametric variation of valve geometry

The influence of inlet valve geometry on IC engine port flow characteristic s was investigated systematically by varying the key valve geometric parame ters of fillet radius, cone angle, and seat angle. The analysis of flow thr ough the port was measured for 36 valves having geometries determined by R/ D =0.20-0.30, cone angle 0-20 deg and seat angle 30-45 deg. Discharge coeff icients were measured to gain an understanding of the general flow performa nce. These were used in conjunction with hear transfer data to gain a clear understanding of the state of the boundary layer on the valve and port sea ls for varying lifts and pressure drops, This established the presence or o therwise of the four flow regimes within the valve passage. The results dem onstrate that the cone and seat angle have major effects on valve pow perfo rmance and enable engine designers to choose more readily the valve charact eristics they desire.