Imperial College London
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Dr. Oliver Buxton

Faculty of Engineering, Department of Aeronautics

Reader in Experimental Fluid Mechanics
 
 
 
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Contact

 

+44 (0)20 7594 5118o.buxton Website CV

 
 
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Location

 

213City and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Baj:2017:10.1103/PhysRevFluids.2.114607,
author = {Baj, P and Buxton, O},
doi = {10.1103/PhysRevFluids.2.114607},
journal = {Physical Review Fluids},
title = {Interscale energy transfer in the merger of wakes of multi-scale arrays of rectangular cylinders},
url = {http://dx.doi.org/10.1103/PhysRevFluids.2.114607},
volume = {2},
year = {2017}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The near wake of a flow past a multiscale array of bars is studied by means of particle image velocimetry (PIV). The aim of this research is to understand the nature of multiscale flows, where multiple coherent motions of nonuniform sizes and characteristic frequencies (i.e., sheddings of particular bars in our considered case) interact with each other. The velocity fields acquired from the experiments are triple decomposed into their mean, a number of coherent fluctuations, and their stochastic part according to a triple decomposition technique introduced recently by Baj et al., Phys. Fluids 27, 075104 (2015). This nonstandard approach allows us to monitor the interactions between different coherent fluctuations representative of sheddings of the particular bars. Further, additional equations governing the kinetic energy of the recognized velocity components are derived to provide better insight into the dynamics of these interactions. Interestingly, apart from the coherent fluctuations associated with sheddings, some additional, secondary coherent fluctuations are also recognized. These seem to appear as a result of nonlinear triadic interactions between the primary shedding modes when the two shedding structures of different characteristic frequencies are in close proximity to one another. The secondary coherent motions are almost exclusively supplied with energy by the primary coherent motions, whereas the latter are driven by the mean flow. It is also found that the coherent fluctuations play an important role in exciting the stochastic fluctuations, as the energy is not fed to the stochastic fluctuations directly from the mean flow but rather through the coherent modes.
AU  - Baj,P
AU  - Buxton,O
DO  - 10.1103/PhysRevFluids.2.114607
PY  - 2017///
SN  - 2469-990X
TI  - Interscale energy transfer in the merger of wakes of multi-scale arrays of rectangular cylinders
T2  - Physical Review Fluids
UR  - http://dx.doi.org/10.1103/PhysRevFluids.2.114607
UR  - http://hdl.handle.net/10044/1/54241
VL  - 2
ER  -
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