Imperial College London
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DrPaulBruce

Faculty of Engineering, Department of Aeronautics

Reader in High-Speed Aerodynamics
 
 
 
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Contact

 

+44 (0)20 7594 5048p.bruce

 
 
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Location

 

333City and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Baj:2015:10.1063/1.4923744,
author = {Baj, P and Bruce, PJK and Buxton, ORH},
doi = {10.1063/1.4923744},
journal = {Physics of Fluids},
pages = {075104--1--075104--24},
title = {The triple decomposition of a fluctuating velocity field in a multiscale flow},
url = {http://dx.doi.org/10.1063/1.4923744},
volume = {27},
year = {2015}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - A new method for the triple decomposition of a multiscale flow, which is based on the novel optimal mode decomposition (OMD) technique, is presented. OMD provides low order linear dynamics, which fits a given data set in an optimal way and is used to distinguish between a coherent (periodic) part of a flow and a stochastic fluctuation. The method needs no external phase indication since this information, separate for coherent structures associated with each length scale introduced into the flow, appears as the output. The proposed technique is compared against two traditional methods of the triple decomposition, i.e., bin averaging and proper orthogonal decomposition. This is done with particle image velocimetry data documenting the near wake of a multiscale bar array. It is shown that both traditional methods are unable to provide a reliable estimation for the coherent fluctuation while the proposed technique performs very well. The crucial result is that the coherence peaks are not observed within the spectral properties of the stochastic fluctuation derived with the proposed method; however, these properties remain unaltered at the residual frequencies. This proves the method’s capability of making a distinction between both types of fluctuations. The sensitivity to some prescribed parameters is checked revealing the technique’s robustness. Additionally, an example of the method application for analysis of a multiscale flow is given, i.e., the phase conditioned transverse integral length is investigated in the near wake region of the multiscale object array.
AU  - Baj,P
AU  - Bruce,PJK
AU  - Buxton,ORH
DO  - 10.1063/1.4923744
EP  - 1
PY  - 2015///
SN  - 1070-6631
SP  - 075104
TI  - The triple decomposition of a fluctuating velocity field in a multiscale flow
T2  - Physics of Fluids
UR  - http://dx.doi.org/10.1063/1.4923744
UR  - https://aip.scitation.org/doi/10.1063/1.4923744
UR  - http://hdl.handle.net/10044/1/25037
VL  - 27
ER  -
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