Accurate Measurement of Displacement by Means of Sound Frequency in a Resonant Pipe : Theoretical Analysis of Sound Frequency by Blowing an Air Jet onto the Open End of a Pipe

Abstract

Sound generates when compressed air is blown onto the open-ended face of a small pipe. The sound frequency varies with the displacement of a solid placed close to another open-ended face of the pipe. This paper deals with the theoretical analysis of the sound frequency generated on the pipe. A theoretical investigation considers air jet behavior on the open-ended face, and the sound impedances both inside and outside of the pipe. The results of sample calculations for the theoretical frequency equation and the experiments coincide significantly for cases of large displacement ; however differences between both results are observed for cases of smaller displacement.