水撃音響法におけるウォータジェットの加振力

抄録

In the impact acoustic method the excitation force has to contain the frequency of the defects which should be detected. The frequency of a steel ball impact is able to be obtained from the change of the contact force with respect to the time. However the mechanism of the excitation due to water jet is different from the elastic ball, which is generated from the momentum conversion into impulse. In this paper the excitation force of water jet impact was measured by a pressure sensor and compared with the simulation results which was obtained from the water droplet intervals and the size. The frequency range of water droplets discharged from a 5 mm nozzle was up to 2.0 kHz.