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Three-dimensional Particle Tracking Velocimetry for Turbulence Applications: Case of a Jet Flow
Published on: February 27, 2016
High order Lagrangian velocity statistics in turbulence
Haitao Xu1, Mickaël Bourgoin, Nicholas T Ouellette
1Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, USA.
Physical Review Letters
|February 21, 2006
Summary
Lagrangian velocity structure functions in high Reynolds number turbulence show greater intermittency than Eulerian counterparts. Classical scaling behavior emerges at shorter times as structure function order increases.
Area of Science:
- Fluid Dynamics
- Turbulence Research
- Statistical Mechanics
Background:
- High Reynolds number turbulence exhibits complex dynamics.
- Lagrangian and Eulerian descriptions offer different perspectives on fluid flow.
- Anomalous scaling in structure functions indicates deviations from simple turbulence theories.
Purpose of the Study:
- To measure Lagrangian velocity structure functions up to order 10.
- To investigate anomalous scaling exponents and intermittency.
- To analyze the emergence of classical Kolmogorov scaling.
Main Methods:
- Optical tracking of passive tracer particles in 3D and time.
- Calculation of particle velocities from trajectory data.
- Direct measurement and extended self-similarity for scaling exponents.
Main Results:
- Lagrangian structure functions exhibit enhanced intermittency compared to Eulerian.
- Classical Kolmogorov inertial range scaling is observed for all orders.
- The onset of classical scaling shifts to shorter times with increasing order.
Conclusions:
- Lagrangian measurements reveal more intermittent turbulence statistics.
- Extended self-similarity aids in analyzing scaling behavior.
- The findings provide insights into the fundamental nature of turbulent flows.
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