This paper deals with the cavitation characteristics in poppet valves, especially as regards the pressure distribution along the valve seat and valve chamber surface, the thrust and transverse vibration of various valves which can be obtained by changing the combinations of the valve face angle 2a, the valve seat width s and valve chamber diameter D.
The results obtained are as follows: 1) In case of s/d = 1, 2 (d: inlet diameter of the valve) the pressure of the valve seat surface indicates the minimum value just behind the upstream edge of the valve seat or just before edge of the valve seat and is slightly higher than those in the middle region.
2) In case of D/d= 6, 10 for each combination of s/d and 2α, upstream pressure along the valve chamber is lower than downstream one.
3) In case of a valve with one combination of s/d = 0.25, 0.5 and a valve face angle of 2α = 30°, 60° in cavitating flow, there is little difference between thrust coefficient f obtained from the pressure distribution along the valve face and thrust coefficient fm, calculated by the momentum theory, for all the values of the sectional area A(H) of the annular passage way of the valve and upstream P1, but in case of s/d =1, 2, there is a small difference between f and fm
4) The stability for transverse vibration of the poppet valve in cavitating flow is affected by various parameters; s/d, 2α, P1 and A(H).
Namely, in case of a large A(H), lower P1, indicates better stability against valve vibrations for each s/d.
Furthermore, as the value of s/d becomes larger, the range of A(H), which is able to stabilize the valve's vibrations, becomes larger under the condition where P1 is constant.