Imperial College London
Alternate

ProfessorGeorgePapadakis

Faculty of Engineering, Department of Aeronautics

Professor of Aerodynamics
 
 
 
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Contact

 

+44 (0)20 7594 5080g.papadakis

 
 
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Location

 

331City and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Guzman:2019:10.1103/PhysRevFluids.4.114703,
author = {Guzman, Inigo J and Sodar, M and Papadakis, G},
doi = {10.1103/PhysRevFluids.4.114703},
journal = {Physical Review Fluids},
title = {A data-based, reduced-order, dynamic estimator for reconstruction of non-linear flows exhibiting limit-cycle oscillations},
url = {http://dx.doi.org/10.1103/PhysRevFluids.4.114703},
volume = {4},
year = {2019}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - We apply a data-based, linear dynamic estimator to reconstruct the velocity field from measurements at a single sensor point in the wake of an aerofoil. In particular, we consider a NACA0012aerofoil at Re = 600 and 16 angle of attack. Under these conditions, the flow exhibits a vortexshedding limit cycle. A reduced order model (ROM) of the flow field is extracted using proper orthogonal decomposition (POD). Subsequently, a subspace system identification algorithm (N4SID)is applied to extract directly the estimator matrices from the reduced output of the system (thePOD coefficients). We explore systematically the effect of the number of states of the estimator,the sensor location, the type of sensor measurements (one or both velocity components), and thenumber of POD modes to be recovered. When the signal of a single velocity component (in thestream wise or cross stream directions) is measured, the reconstruction of the first two dominantPOD modes strongly depends on the sensor location. We explore this behaviour and provide aphysical explanation based on the non-linear mode interaction and the spatial distribution of themodes. When however, both components are measured, the performance is very robust, and isalmost independent of the sensor location when the optimal number of estimator states is used.Reconstruction of the less energetic modes is more difficult, but still possible. Finally, we assessthe robustness of the estimator at off-design conditions, at Re = 550 and 650.`
AU  - Guzman,Inigo J
AU  - Sodar,M
AU  - Papadakis,G
DO  - 10.1103/PhysRevFluids.4.114703
PY  - 2019///
SN  - 2469-990X
TI  - A data-based, reduced-order, dynamic estimator for reconstruction of non-linear flows exhibiting limit-cycle oscillations
T2  - Physical Review Fluids
UR  - http://dx.doi.org/10.1103/PhysRevFluids.4.114703
UR  - http://hdl.handle.net/10044/1/74329
VL  - 4
ER  -
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