Turbulence spectra from a tidal channel

Abstract

This paper describes the use of a hot film flowmeter in the sea and presents experimental measurements of the ‘downstream’ component of turbulent velocity in a tidal channel. The Reynolds number of the flow is about 108 and the scale of the turbulence is so large that a ship is carried about to a considerable extent by the energy-containing eddies. Under these conditions, a velocity measuring probe attached to a ship cannot be used for reliable measurements in the energy-containing range of the spectrum. It is possible, however, to observe the intertial and dissipation ranges. Records have been made at various stages of the tide. The one-dimensional spectra are found to be proportional to $k|^{-{\frac {5}{3}}}$ for several decades in k as predicted by Kolmogoroff, and a value is given for Kolmogoroff's constant. In the dissipation range there is close agreement with both Kovasznay's theory and Heisenberg's theory. These two theories are not very different in the low wave-number end of the range and the observations do not extend to high enough wave-numbers to distinguish between them.

The inertial subrange in turbulent pipe flow: centreline

“…The spectral form of K41 -as postulated by Obukhov (1962) -has received support from many experiments both in the atmosphere and in the ocean (see for example, Grant et al 1962), both in the form of the inertial subrange law as well as the collapse of spectra exhibiting universal equilibrium. Yet, questions remain and laboratory experiments in a single facility in which the boundary conditions are well controlled are few.…”

Statistical properties of turbulence: An overview

“…Electromagnetically forced thin films and soap films [1,35,36] have yielded very useful results for two-dimensional turbulence. Turbulence data can also be obtained from atmospheric boundary layers [61][62][63][64], oceanic flows [65], and astrophysical measurements [14]; experimental conditions cannot be controlled as carefully in such natural settings as they can be in a laboratory, but a far greater range of length scales can be probed than is possible in laboratory experiments.…”

Solar Wind Turbulence and the Role of Ion Instabilities

“…Note that Kolmogorov 4/5 law can be obtained from the more general Yaglom (1949) law in case of Navier-Stokes isotropic turbulence. When the energy cascade "arrives" to the spatial (or time) scale of the order of the dissipation scale d , the spectrum becomes curved (Grant et al 1962), indicating a lack of self-similarity. This spectrum is also universal (see, e.g., Fig.…”