Effects of refraction by means flow velocity gradients on the standing wave pattern in three-dimensional, rectangular waveguides
Abstract
The influence of a mean vortical flow on the connection between the standing wave pattern in a rectangular three dimensional waveguide and the corresponding duct axial impedance was determined analytically. The solution was derived using a perturbation scheme valid for low mean flow Mach numbers and plane wave sound frequencies. The results show that deviations of the standing wave pattern due to refraction by the mean flow gradients are small.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- June 1979
- Bibcode:
- 1979STIN...7933375H
- Keywords:
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- Acoustic Impedance;
- Flow Velocity;
- Refraction;
- Waveguides;
- Ducts;
- Perturbation;
- Plane Waves;
- Vortices;
- Communications and Radar