article · Journal of Fluid Mechanics · 1981
Sound diffraction at a trailing edge
Cited by 0Abstract and details only
Abstract
The diffraction of externally generated sound in a uniformly moving flow at the trailing edge of a semi-infinite flat plate is studied. In particular, the coupling of the sound field to the hydrodynamic field by way of vortex shedding from the edge is considered in detail, both in inviscid and in viscous flow. In the inviscid model the (two-dimensional) diffracted fields of a cylindrical pulse wave, a plane harmonic wave and a plane pulse wave are calculated. The viscous proess of vortex shedding is represented by an appropriate trailing-edge condition. Two specific cases are compared, in one of which the full Kutta condition is applied, and in the other no vortex shedding is permitted. The results show good agreement with Heavens’ (1978) observations from his schlieren photographs, and confirm his conclusions. It is further demonstrated, by an explicit expression, that the sound power absorbed by the wake may be positive or negative, depending on Mach number and source position. So the process of vortex shedding does not necessarily imply an attenuation of the sound. In the viscous model a high-Reynolds-number approximation is constructed, based on a triple-deck boundary-layer structure, matching the harmonic plane wave outer solution to a known incompressible inner solution near the edge, to obtain the viscous correction to the Kutta condition.
Cite this paper
Rienstra, S. (1981). Sound diffraction at a trailing edge. Journal of Fluid Mechanics, 108(8), 443–460. https://doi.org/10.1017/s0022112081002206
Rienstra, S.W. “Sound diffraction at a trailing edge.” Journal of Fluid Mechanics, vol. 108, no. 8, 1981, pp. 443–60, https://doi.org/10.1017/s0022112081002206.
Rienstra, S.W. 1981. “Sound diffraction at a trailing edge.” Journal of Fluid Mechanics 108 (8): 443–60. https://doi.org/10.1017/s0022112081002206.
Rienstra, S. (1981) ‘Sound diffraction at a trailing edge’, Journal of Fluid Mechanics, 108(8), pp. 443–460. Available at: https://doi.org/10.1017/s0022112081002206.
@article{rienstra1981sound,
title = {{Sound diffraction at a trailing edge}},
author = {Rienstra, S.W.},
journal = {Journal of Fluid Mechanics},
volume = {108},
number = {8},
pages = {443--460},
year = {1981},
doi = {10.1017/s0022112081002206}
}Made from the index record. Check names, capitalisation and page numbers against the paper. Need another style? AI for Research has over 10,000.