Soap film flows: Statistics of two-dimensional turbulence

Journal Article · Sun Aug 01 04:00:00 EDT 1999 · Physics of Fluids (1994)

DOI:https://doi.org/10.1063/1.870078· OSTI ID:351858

Vorobieff, P; Rivera, M; Ecke, R E ^[1]

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1. Center for Nonlinear Studies and Condensed Matter and Thermal Physics Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

Soap film flows provide a very convenient laboratory model for studies of two-dimensional (2-D) hydrodynamics including turbulence. For a gravity-driven soap film channel with a grid of equally spaced cylinders inserted in the flow, we have measured the simultaneous velocity and thickness fields in the irregular flow downstream from the cylinders. The velocity field is determined by a modified digital particle image velocimetry method and the thickness from the light scattered by the particles in the film. From these measurements, we compute the decay of mean energy, enstrophy, and thickness fluctuations with downstream distance, and the structure functions of velocity, vorticity, thickness fluctuation, and vorticity flux. From these quantities we determine the microscale Reynolds number of the flow R{sub {lambda}}{approx}100 and the integral and dissipation scales of 2D turbulence. We also obtain quantitative measures of the degree to which our flow can be considered incompressible and isotropic as a function of downstream distance. We find coarsening of characteristic spatial scales, qualitative correspondence of the decay of energy and enstrophy with the Batchelor model, scaling of energy in {ital k} space consistent with the k{sup {minus}3} spectrum of the Kraichnan{endash}Batchelor enstrophy-scaling picture, and power-law scalings of the structure functions of velocity, vorticity, vorticity flux, and thickness. These results are compared with models of 2-D turbulence and with numerical simulations. {copyright} {ital 1999 American Institute of Physics.}

• OSTI ID: 351858
• Journal Information: Physics of Fluids (1994), Journal Name: Physics of Fluids (1994) Journal Issue: 8 Vol. 11; ISSN PHFLE6; ISSN 1070-6631
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ENERGY TRANSFER
FILM FLOW
HYDRODYNAMICS
SOAPS
STATISTICS
THICKNESS
THIN FILMS
TURBULENCE
TURBULENT FLOW
TWO-DIMENSIONAL CALCULATIONS
VELOCITY
VORTICES