### Abstract

The consept of flow field velocimetry based on scalar imaging measurements [Phys. Fluids A 4, 2191 (1992)] is here formulated in terms of an integral minimization implementation, where the velocity field u(x,t) is found by minimizing weighted residuals of the conserved scalar transport equation, along with the continuity condition and a smoothness condition. We apply this technique to direct numerical simulation (DNS) data for the limiting case of turbulent mixing of a Sc= 1 passive scalar field. The spatial velocity fields u(x,t) thus obtained demonstrate good correlation with the exact DNS fields, as do the statistics of the velocity and the velocity gradient fields. The results from this integral minimization implementation also show significant improvement over those from the direct inversion technique reported earlier. These results are shown to be largely insensitive to noise at levels characteristic of current fully resolved scalar field measurements.

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

Pages (from-to) | 1869-1882 |

Number of pages | 14 |

Journal | Physics of Fluids |

Volume | 8 |

Issue number | 7 |

State | Published - Jul 1996 |

Externally published | Yes |

### Fingerprint

### ASJC Scopus subject areas

- Fluid Flow and Transfer Processes
- Computational Mechanics
- Mechanics of Materials
- Physics and Astronomy(all)
- Condensed Matter Physics

### Cite this

*Physics of Fluids*,

*8*(7), 1869-1882.

**Scalar imaging velocimetry measurements of the velocity gradient tensor field in turbulent flows. I. Assessment of errors.** / Su, Lester K.; Dahm, Werner.

Research output: Contribution to journal › Article

*Physics of Fluids*, vol. 8, no. 7, pp. 1869-1882.

}

TY - JOUR

T1 - Scalar imaging velocimetry measurements of the velocity gradient tensor field in turbulent flows. I. Assessment of errors

AU - Su, Lester K.

AU - Dahm, Werner

PY - 1996/7

Y1 - 1996/7

N2 - The consept of flow field velocimetry based on scalar imaging measurements [Phys. Fluids A 4, 2191 (1992)] is here formulated in terms of an integral minimization implementation, where the velocity field u(x,t) is found by minimizing weighted residuals of the conserved scalar transport equation, along with the continuity condition and a smoothness condition. We apply this technique to direct numerical simulation (DNS) data for the limiting case of turbulent mixing of a Sc= 1 passive scalar field. The spatial velocity fields u(x,t) thus obtained demonstrate good correlation with the exact DNS fields, as do the statistics of the velocity and the velocity gradient fields. The results from this integral minimization implementation also show significant improvement over those from the direct inversion technique reported earlier. These results are shown to be largely insensitive to noise at levels characteristic of current fully resolved scalar field measurements.

AB - The consept of flow field velocimetry based on scalar imaging measurements [Phys. Fluids A 4, 2191 (1992)] is here formulated in terms of an integral minimization implementation, where the velocity field u(x,t) is found by minimizing weighted residuals of the conserved scalar transport equation, along with the continuity condition and a smoothness condition. We apply this technique to direct numerical simulation (DNS) data for the limiting case of turbulent mixing of a Sc= 1 passive scalar field. The spatial velocity fields u(x,t) thus obtained demonstrate good correlation with the exact DNS fields, as do the statistics of the velocity and the velocity gradient fields. The results from this integral minimization implementation also show significant improvement over those from the direct inversion technique reported earlier. These results are shown to be largely insensitive to noise at levels characteristic of current fully resolved scalar field measurements.

UR - http://www.scopus.com/inward/record.url?scp=0029671772&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029671772&partnerID=8YFLogxK

M3 - Article

VL - 8

SP - 1869

EP - 1882

JO - Physics of Fluids

JF - Physics of Fluids

SN - 1070-6631

IS - 7

ER -