Youngpil Kwon
Alan Powell
Dept. of Mech. Eng., Univ. of Houston, Houston, TX 77204-4792
A theoretical model is presented to explain the jet--edge interaction and
the sound radiation. The aerodynamic response of the edge to the sinuous
impinging jet is obtained by regarding the edge reaction as the surface
distribution of dipoles necessary to meet the local boundary condition. Then
the sound radiation is estimated using these dipoles. The relationship between
the jet sinuosity and the sound radiation is quantified: The pressure field on
the edge and the directivity of the sound radiation is estimated. It is found
that the effective point source is located about a quarter wavelength
downstream from the edge tip. The effect of the edge configuration and the jet
velocity on the magnitude and directivity of the sound radiation is estimated.
This simple model is consistent with available experimental data for low- and
high-speed edge tones. [Partial support from Korean Science and Engineering
Foundation and the Texas Advanced Research Program.]