Understanding energy balance in complex turbulent fluids, e.g. in the ocean and atmosphere, remains a challenging problem of the utmost importance. The direction of the energy flux in turbulence can reveal energy sources powering atmospheric winds at different heights in the troposphere and lower stratosphere. To unambiguously resolve the issue of the turbulent energy transfer, one needs to develop a practically suitable method for measuring the spectral energy flux in atmospheric turbulence. The flux can be determined using the Kolmogorov law, which relates the flux to the third-order moment of velocities. This requires simultaneous measurement of velocities at very large number of spatial locations on a grid, which is achievable in a small-scale laboratory experiments, but is not practically possible in atmospheric applications. In this project, we propose to base the determination of the energy flux on a two-point measurement of the velocity fluctuations. In the laboratory experiments such a method can also be cross-tested by the Kolmogorov law method. Then this new method of the spectral transfer analysis will be used in the proposed studies of atmospheric wind measurements.
- Hotwire measurements of turbulent velocities in thin fluid layer experiments
- Power transfer function analysis of laboratory 2D experiments and cross-calibration with the Kolmogorov flux relation