richter_iaccarino_shaqfeh12

Summary

Effect of viscoelasticity in the high Reynolds number cylinder wake. D. Richter, G. Iaccarino and E.S.G. Shaqfeh. Journal of Fluid Mechanics, 693:297-318, 2012. (URL)

Abstract

At $\mathit{Re}= 3900$, Newtonian flow past a circular cylinder exhibits a wake and detached shear layers which have transitioned to turbulence. It is the goal of the present study to investigate the effects which viscoelasticity has on this state and to identify the mechanisms responsible for wake stabilization. It is found through numerical simulations (employing the FENE-P rheological model) that viscoelasticity greatly reduces the amount of turbulence in the wake, reverting it back to a state which qualitatively appears similar to the Newtonian mode B instability which occurs at lower $\mathit{Re}$. By focusing on the separated shear layers, it is found that viscoelasticity suppresses the formation of the Kelvin-Helmholtz instability which dominates for Newtonian flows, consistent with previous studies of viscoelastic free shear layers. Through this shear layer stabilization, the viscoelastic far wake is then subject to the same instability mechanisms which dominate for Newtonian flows, but at far lower Reynolds numbers.

Bibtex entry

@ARTICLE { richter_iaccarino_shaqfeh12,
    AUTHOR = { D. Richter and G. Iaccarino and E.S.G. Shaqfeh },
    TITLE = { Effect of viscoelasticity in the high Reynolds number cylinder wake },
    JOURNAL = { Journal of Fluid Mechanics },
    VOLUME = { 693 },
    PAGES = { 297-318 },
    YEAR = { 2012 },
    ABSTRACT = { At $\mathit{Re}= 3900$, Newtonian flow past a circular cylinder exhibits a wake and detached shear layers which have transitioned to turbulence. It is the goal of the present study to investigate the effects which viscoelasticity has on this state and to identify the mechanisms responsible for wake stabilization. It is found through numerical simulations (employing the FENE-P rheological model) that viscoelasticity greatly reduces the amount of turbulence in the wake, reverting it back to a state which qualitatively appears similar to the Newtonian mode B instability which occurs at lower $\mathit{Re}$. By focusing on the separated shear layers, it is found that viscoelasticity suppresses the formation of the Kelvin-Helmholtz instability which dominates for Newtonian flows, consistent with previous studies of viscoelastic free shear layers. Through this shear layer stabilization, the viscoelastic far wake is then subject to the same instability mechanisms which dominate for Newtonian flows, but at far lower Reynolds numbers. },
    URL = { http://dx.doi.org/10.1017/jfm.2011.531 },
}