EMISSION OF A PROPAGATING COMPRESSION WAVE FROM AN OPEN-END OF A TUBE(EXPERIMENT ON MAGNITUDE OF EMITTED IMPULSIVE WAVE)

An experimental study is carried out on the emission of a propagating compression wave from an open end of a tube. A shock tube with a fast opening gate valve instead of a diaphragm is employed for producing co mpression waves of various strength. The magnitude of the impulsive wa ve emitted from an open end is compared with the results of aeroacoust ic analysis presented in the previous reports. The directivity of the impulsive wave and its attenuation with distance are discussed. It has been shown that the magnitude of the emitted impulsive wave agrees we ll with the results of the aeroacoustic analysis, and the directivity of the impulsive wave is independent of the strength of the compressio n wave but depends on the length of the compression wave.