### Abstract

An experimental investigation of the two-dimensional incompressible mixing layer was carried out. The relevance of initial conditions to the development of the flow is discussed in the light of both present and previous data. Measurements of spectra, probability densities and moments to eighth order of all three velocity-component fluctuations at various transverse positions across the flow were carried out using an on-line digital data acquisition system. The probability density distributions of the derivative and the squared derivative of the longitudinal and lateral velocity fluctuations were also determined. Direct measurements of moments to eighth order of the velocity derivatives were attempted and are discussed in the light of the simultaneously measured histograms. The problems in obtaining higher-order statistical data are considered in some detail. Estimates of the integral time scale of many of the higher-order statistics are presented. The high wave-number structure was found to be locally anisotropic according to both spectral and turbulent velocity-gradient moment requirements. The measurements provided new information on the development of the mean and turbulent fields towards a self-preserving state and on the higher-order statistical characteristics of the turbulent field.

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

Pages (from-to) | 209-250 |

Number of pages | 42 |

Journal | Journal of Fluid Mechanics |

Volume | 74 |

Issue number | pt 2 |

State | Published - Jan 1 1976 |

Externally published | Yes |

### Fingerprint

### ASJC Scopus subject areas

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

### Cite this

*Journal of Fluid Mechanics*,

*74*(pt 2), 209-250.

**ON THE TWO-DIMENSIONAL MIXING REGION.** / Champagne, F. H.; Pao, Y. H.; Wygnanski, Israel J.

Research output: Contribution to journal › Article

*Journal of Fluid Mechanics*, vol. 74, no. pt 2, pp. 209-250.

}

TY - JOUR

T1 - ON THE TWO-DIMENSIONAL MIXING REGION.

AU - Champagne, F. H.

AU - Pao, Y. H.

AU - Wygnanski, Israel J

PY - 1976/1/1

Y1 - 1976/1/1

N2 - An experimental investigation of the two-dimensional incompressible mixing layer was carried out. The relevance of initial conditions to the development of the flow is discussed in the light of both present and previous data. Measurements of spectra, probability densities and moments to eighth order of all three velocity-component fluctuations at various transverse positions across the flow were carried out using an on-line digital data acquisition system. The probability density distributions of the derivative and the squared derivative of the longitudinal and lateral velocity fluctuations were also determined. Direct measurements of moments to eighth order of the velocity derivatives were attempted and are discussed in the light of the simultaneously measured histograms. The problems in obtaining higher-order statistical data are considered in some detail. Estimates of the integral time scale of many of the higher-order statistics are presented. The high wave-number structure was found to be locally anisotropic according to both spectral and turbulent velocity-gradient moment requirements. The measurements provided new information on the development of the mean and turbulent fields towards a self-preserving state and on the higher-order statistical characteristics of the turbulent field.

AB - An experimental investigation of the two-dimensional incompressible mixing layer was carried out. The relevance of initial conditions to the development of the flow is discussed in the light of both present and previous data. Measurements of spectra, probability densities and moments to eighth order of all three velocity-component fluctuations at various transverse positions across the flow were carried out using an on-line digital data acquisition system. The probability density distributions of the derivative and the squared derivative of the longitudinal and lateral velocity fluctuations were also determined. Direct measurements of moments to eighth order of the velocity derivatives were attempted and are discussed in the light of the simultaneously measured histograms. The problems in obtaining higher-order statistical data are considered in some detail. Estimates of the integral time scale of many of the higher-order statistics are presented. The high wave-number structure was found to be locally anisotropic according to both spectral and turbulent velocity-gradient moment requirements. The measurements provided new information on the development of the mean and turbulent fields towards a self-preserving state and on the higher-order statistical characteristics of the turbulent field.

UR - http://www.scopus.com/inward/record.url?scp=0016934807&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0016934807&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0016934807

VL - 74

SP - 209

EP - 250

JO - Journal of Fluid Mechanics

JF - Journal of Fluid Mechanics

SN - 0022-1120

IS - pt 2

ER -