### Abstract

A time-averaged length scale can be defined by a pair of successive turbulent-velocity derivatives, i.e. [d^{n}u(x)/dx^{n}]′/[d^{n+1}u(x)/dx ^{n+1}]′. The length scale associated with the zeroth- and the first-order derivatives, u′/u′_{x}, is the Taylor microscale. In isotropic turbulence, this scale is the average length between zero crossings of the velocity signal. The average length between zero crossings of the first velocity derivative, i.e. u′_{x}/u′_{xx}, can be reliably obtained by using the peak-valley-counting (PVC) technique. We have found that the most probable scale, rather than the average, equals the wavelength at the peak of the dissipation spectrum in a plane mixing layer (Zohar & Ho 1996). In this study, we experimentally investigate the generality of applying the PVC technique to estimate the dissipation scale in three basic turbulent shear flows: a flat-plate boundary layer, a wake behind a two-dimensional cylinder and a plane mixing layer. We also analytically explore the quantitative relationships among this length scale and the Kolmogorov and Taylor microscales.

Original language | English (US) |
---|---|

Pages (from-to) | 135-159 |

Number of pages | 25 |

Journal | Journal of Fluid Mechanics |

Volume | 352 |

State | Published - Dec 10 1997 |

Externally published | Yes |

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### ASJC Scopus subject areas

- Computational Mechanics
- Mechanics of Materials
- Physics and Astronomy(all)
- Condensed Matter Physics

### Cite this

*Journal of Fluid Mechanics*,

*352*, 135-159.

**The PVC technique - A method to estimate the dissipation length scale in turbulent flows.** / Ho, Chih Ming; Zohar, Yitshak.

Research output: Contribution to journal › Article

*Journal of Fluid Mechanics*, vol. 352, pp. 135-159.

}

TY - JOUR

T1 - The PVC technique - A method to estimate the dissipation length scale in turbulent flows

AU - Ho, Chih Ming

AU - Zohar, Yitshak

PY - 1997/12/10

Y1 - 1997/12/10

N2 - A time-averaged length scale can be defined by a pair of successive turbulent-velocity derivatives, i.e. [dnu(x)/dxn]′/[dn+1u(x)/dx n+1]′. The length scale associated with the zeroth- and the first-order derivatives, u′/u′x, is the Taylor microscale. In isotropic turbulence, this scale is the average length between zero crossings of the velocity signal. The average length between zero crossings of the first velocity derivative, i.e. u′x/u′xx, can be reliably obtained by using the peak-valley-counting (PVC) technique. We have found that the most probable scale, rather than the average, equals the wavelength at the peak of the dissipation spectrum in a plane mixing layer (Zohar & Ho 1996). In this study, we experimentally investigate the generality of applying the PVC technique to estimate the dissipation scale in three basic turbulent shear flows: a flat-plate boundary layer, a wake behind a two-dimensional cylinder and a plane mixing layer. We also analytically explore the quantitative relationships among this length scale and the Kolmogorov and Taylor microscales.

AB - A time-averaged length scale can be defined by a pair of successive turbulent-velocity derivatives, i.e. [dnu(x)/dxn]′/[dn+1u(x)/dx n+1]′. The length scale associated with the zeroth- and the first-order derivatives, u′/u′x, is the Taylor microscale. In isotropic turbulence, this scale is the average length between zero crossings of the velocity signal. The average length between zero crossings of the first velocity derivative, i.e. u′x/u′xx, can be reliably obtained by using the peak-valley-counting (PVC) technique. We have found that the most probable scale, rather than the average, equals the wavelength at the peak of the dissipation spectrum in a plane mixing layer (Zohar & Ho 1996). In this study, we experimentally investigate the generality of applying the PVC technique to estimate the dissipation scale in three basic turbulent shear flows: a flat-plate boundary layer, a wake behind a two-dimensional cylinder and a plane mixing layer. We also analytically explore the quantitative relationships among this length scale and the Kolmogorov and Taylor microscales.

UR - http://www.scopus.com/inward/record.url?scp=0031378263&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031378263&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0031378263

VL - 352

SP - 135

EP - 159

JO - Journal of Fluid Mechanics

JF - Journal of Fluid Mechanics

SN - 0022-1120

ER -