Emission of a Propagating Compression Wave from an Open End of a Tube : 3rd Report, Experiment on Magnitude of Emitted Impulsive Wave

Abstract

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 compression waves of various strengths. The magnitude of the impulsive wave emitted from the open end is compared with the results of aeroacoustic 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 well with the results calculated by the aeroacoustic analysis, and the directivity of the impulsive wave is independent of the strength of the compression wave but depends on the length of the compression wave.