Imperial College London
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Professor Aimee S. Morgans

Faculty of Engineering, Department of Mechanical Engineering

Professor of Thermofluids
 
 
 
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Contact

 

+44 (0)20 7594 9975a.morgans

 
 
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Location

 

621City and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@inproceedings{Guzmán-Iñigo:2022:10.2514/6.2022-2997,
author = {Guzmán-Iñigo, J and Morgans, AS},
doi = {10.2514/6.2022-2997},
title = {Influence of the shape of a short circular hole with bias flow its acoustic response},
url = {http://dx.doi.org/10.2514/6.2022-2997},
year = {2022}
}
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RIS format (EndNote, RefMan)

TY  - CPAPER
AB  - Short circular holes with a mean bias flow passing through them can absorb or generate acoustic energy. This property is relevant for many industrial applications containing holes, such as liners or Helmholtz resonators. A recent theoretical study suggested that the acoustic response of such perforations could be strongly sensitive to small modifications of the geometry of their lips. In this work, we study this sensitivity numerically. To this end, we use a two-step approach, where a steady mean flow is computed first as the solution of the incompressible Reynolds-Averaged Navier-Stokes (RANS) equations. Small-amplitude acoustic perturbations are then superimposed on this mean flow and their dynamics are obtained as the solution of the linearised Navier-Stokes equations (LNSE) with frozen eddy viscosity. The approach is compared with experimental results for a straight hole (with sharp edges) and an excellent agreement is obtained. Two cases with modified edges are then investigated: (i) a hole with a chamfered upstream edge (sharp downstream edge) and (ii) the inverse configuration (chamfered dowstream edge). The chamfer at the upstream edge strongly modifies the acoustic response of the perforation over the range of frequencies investigated. The chamfer at the downstream edge, on the other hand, does not significantly alter it. This work confirms the sensitivity of the acoustic response of the holes to modifications of the upstream-edge geometries and proposes an efficient numerical tool that can be used to design bespoke geometries to leverage this property in industrial applications.
AU  - Guzmán-Iñigo,J
AU  - Morgans,AS
DO  - 10.2514/6.2022-2997
PY  - 2022///
TI  - Influence of the shape of a short circular hole with bias flow its acoustic response
UR  - http://dx.doi.org/10.2514/6.2022-2997
ER  -
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