Abstract
The coherence function was measured from two sampled jet noise signals, one from a stationary microphone and the other from a circumferentially moving microphone. The coherence function was then expanded in a Fourier series with respect to the azimuthal angle. For an axisymmetric circular jet the Fourier coefficients thus obtained are equivalent to the power spectral density of the individual azimuthal constituents of the fluctuating pressure in the radiated field. It was found that for Strouhal numbers less than 1.0, the radiated sound is composed of only a small number of azimuthal components. For higher frequencies, nonaxisymmetric components are predominant. The prediction method for single-azimuth-frequency components proposed by Chan [Y. Y. Chan, AIAA J. 12 (2) (1974)] based on the spectral theory of Michalke has been further developed for the present study. [Work supported by NASA.]
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
