AN EXPERIMENTAL STUDY OF LOW SPEED EDGETONES,
Abstract
This experimental investigation of low speed jet edgetones was performed in connection with the development of the acoustic feedback theory first presented in 1953. Two jet edgetone systems are described. With these systems, variation in the breadth of the stream, the angle of the wedge, and the size of the wedge were made while measurements of edge distance, stream velocity, frequency, sound pressure level and the associated radiation pattern were performed, the exit velocity profile of the stream being controlled. The fluctuating force on the wedge has been measured simultaneously with the far field acoustic pressure, and the results confirm that the acoustic far field can be represented by an equivalent point dipole located in the region of the wedge and whose magnitude corresponds to the measured force. Richardson's 'crucial' experiment has been repeated and the result is consistent with the feedback theory. The experimental results concerning such features as the number of stages, minimum edge distance, and the size and shape of the obstacle are all consistent with the acoustic feedback theory. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1964
- Accession Number
- AD0610028
Entities
People
- Alan Powell
- H. H. Unfried
Organizations
- University of California, Los Angeles