To take up the three-dimensional axisymmetric gate slot concerining with the gate slot possessed in hydraulic equipment, such as, a gate valve, the state of cavitation of the gate slot was investigated by Acoustic Emisson (AE) measurement. The relationship between AE energy level and cavitation condition was analyzed by the root-mean-square (RMS) of acoustic wave. Moreover, a new AE parameter "relative accumulated intensity (RAI)" was defined in order to estimate the erosion tendency of cavitation. Combining with the result of impulsive pressure measurement, the relationship between the erosive damage and the high amplitude generation of AE wave is confirmed by using RAI. In consideration of deflector effect, the AE measurement showed that the conical shape installed on the upstream side of gate slot makes the cavitation erosion increased, and the offset shape on the downstream side of gate slot makes the cavitation erosion decreased significantly.
2011 The Japan Society of Mechanical Engineers