Imperial College London
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DrGeorgiosRigas

Faculty of Engineering, Department of Aeronautics

Senior Lecturer
 
 
 
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Contact

 

+44 (0)20 7594 5065g.rigas CV

 
 
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Location

 

327City and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@inproceedings{Pickering:2019:10.2514/6.2019-2454,
author = {Pickering, E and Rigas, G and Colonius, T and Sipp, D and Schmidt, OT},
doi = {10.2514/6.2019-2454},
title = {Eddy viscosity for resolvent-based jet noise models},
url = {http://dx.doi.org/10.2514/6.2019-2454},
year = {2019}
}
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RIS format (EndNote, RefMan)

TY  - CPAPER
AB  - Response modes computed via linear resolvent analysis have shown promising results for qualitatively modeling both the hydrodynamic and acoustic fields in jets when compared to data-deduced modes from high-fidelity, large-eddy simulations (LES). For an improved quantitative prediction of the near-and far-field, the role of Reynolds stresses must also be considered. In this study, we propose a methodology to deduce an eddy-viscosity model that optimally captures the nonlinear forcing of resolvent modes. The methodology is based on the maximization of the projection between resolvent analysis and spectral proper orthogonal decomposition (SPOD) modes using a Lagrangian optimization framework. For a Mach 0.4 round, isothermal, turbulent jet, four methods are used to increase the projection coefficients: linear damping, spatially constant eddy-viscosity field, a turbulent kinetic energy derived viscosity field, and an optimized eddy-viscosity field. The resulting projection coefficients for the optimized eddy-viscosity field between SPOD and resolvent can be increased to over 90% for frequencies in the range St = 0.35 − 1 with significant improvements to St < 0.35. We find that the use of a frequency-independent turbulent kinetic energy turbulent viscosity model produces modes closely inline with optimal results, providing a preliminary eddy-viscosity resolvent model for jets.
AU  - Pickering,E
AU  - Rigas,G
AU  - Colonius,T
AU  - Sipp,D
AU  - Schmidt,OT
DO  - 10.2514/6.2019-2454
PY  - 2019///
TI  - Eddy viscosity for resolvent-based jet noise models
UR  - http://dx.doi.org/10.2514/6.2019-2454
ER  -
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