### Abstract

Particle Image Velocimetry (PIV) measurements have been acquired in a cylindrical tank stirred by a Rushton turbine. Since the six-bladed Rushton turbine is symmetric with respet to each blade, phase-averaged velocity fields in the r-z plane were required at intervals of 10 degrees within one sextant. Two datasets were acquired, with magnifications of 0.26 and 0.56 respetively. Five mean square gradients are computed from the PIV data and turbulent dissipation is estimated directly using these quantities. Four estimates of dissipation are presented, each based on certain assumptions about the turbulent flow. The first estimate is based only on the measured component υ_{1,1}
^{2}, the second estimate uses all of the available measured components and applies isotropic assumptions for the unknown components. The third and fourth estimates assume that the turbulence is statistically axisymmetric, and assumptions of axisymmetry around two axes are compared. The estimates which assume statistical axisymmetry around the z-axis and the estimate which uses all known components and isotropic assumptions for the unknown components are consistent and appear useful as a lower bound. The estimate which relies only on the measured component u_{1,1}
^{2} appears to be a higher bound.

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

Title of host publication | Proceedings of the 1999 3rd ASME/JSME Joint Fluids Engineering Conference, FEDSM'99, San Francisco, California, USA, 18-23 July 1999 (CD-ROM) |

Publisher | American Society of Mechanical Engineers |

Pages | 1 |

Number of pages | 1 |

ISBN (Print) | 0791819612 |

State | Published - 1999 |

Externally published | Yes |

### Fingerprint

### ASJC Scopus subject areas

- Earth and Planetary Sciences(all)
- Engineering(all)
- Environmental Science(all)

### Cite this

*Proceedings of the 1999 3rd ASME/JSME Joint Fluids Engineering Conference, FEDSM'99, San Francisco, California, USA, 18-23 July 1999 (CD-ROM)*(pp. 1). American Society of Mechanical Engineers.

**A comparison of dissipation estimation methods in a stirred tank using Particle Image Velocimetry (PIV).** / Sharp, K. V.; Kim, K. C.; Adrian, Ronald.

Research output: Chapter in Book/Report/Conference proceeding › Chapter

*Proceedings of the 1999 3rd ASME/JSME Joint Fluids Engineering Conference, FEDSM'99, San Francisco, California, USA, 18-23 July 1999 (CD-ROM).*American Society of Mechanical Engineers, pp. 1.

}

TY - CHAP

T1 - A comparison of dissipation estimation methods in a stirred tank using Particle Image Velocimetry (PIV)

AU - Sharp, K. V.

AU - Kim, K. C.

AU - Adrian, Ronald

PY - 1999

Y1 - 1999

N2 - Particle Image Velocimetry (PIV) measurements have been acquired in a cylindrical tank stirred by a Rushton turbine. Since the six-bladed Rushton turbine is symmetric with respet to each blade, phase-averaged velocity fields in the r-z plane were required at intervals of 10 degrees within one sextant. Two datasets were acquired, with magnifications of 0.26 and 0.56 respetively. Five mean square gradients are computed from the PIV data and turbulent dissipation is estimated directly using these quantities. Four estimates of dissipation are presented, each based on certain assumptions about the turbulent flow. The first estimate is based only on the measured component υ1,1 2, the second estimate uses all of the available measured components and applies isotropic assumptions for the unknown components. The third and fourth estimates assume that the turbulence is statistically axisymmetric, and assumptions of axisymmetry around two axes are compared. The estimates which assume statistical axisymmetry around the z-axis and the estimate which uses all known components and isotropic assumptions for the unknown components are consistent and appear useful as a lower bound. The estimate which relies only on the measured component u1,1 2 appears to be a higher bound.

AB - Particle Image Velocimetry (PIV) measurements have been acquired in a cylindrical tank stirred by a Rushton turbine. Since the six-bladed Rushton turbine is symmetric with respet to each blade, phase-averaged velocity fields in the r-z plane were required at intervals of 10 degrees within one sextant. Two datasets were acquired, with magnifications of 0.26 and 0.56 respetively. Five mean square gradients are computed from the PIV data and turbulent dissipation is estimated directly using these quantities. Four estimates of dissipation are presented, each based on certain assumptions about the turbulent flow. The first estimate is based only on the measured component υ1,1 2, the second estimate uses all of the available measured components and applies isotropic assumptions for the unknown components. The third and fourth estimates assume that the turbulence is statistically axisymmetric, and assumptions of axisymmetry around two axes are compared. The estimates which assume statistical axisymmetry around the z-axis and the estimate which uses all known components and isotropic assumptions for the unknown components are consistent and appear useful as a lower bound. The estimate which relies only on the measured component u1,1 2 appears to be a higher bound.

UR - http://www.scopus.com/inward/record.url?scp=0033394240&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033394240&partnerID=8YFLogxK

M3 - Chapter

AN - SCOPUS:0033394240

SN - 0791819612

SP - 1

BT - Proceedings of the 1999 3rd ASME/JSME Joint Fluids Engineering Conference, FEDSM'99, San Francisco, California, USA, 18-23 July 1999 (CD-ROM)

PB - American Society of Mechanical Engineers

ER -