A novel method for three-dimensional three-component analysis of flows close to free water surfaces

Jehle, Markus; Jähne, Bernd

doi:10.1007/s00348-007-0453-5

Cited by 9 publications

(11 citation statements)

References 16 publications

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“…In the recent past many methods were proposed to access volumetric information from 3D flow fields. This was achieved using holographic measurements (Hinsch 2002;Sheng et al 2008), by combining PIV with Doppler global velocimetry (PIV/DGV) (Wernet 2004), using tomography (Elsinga et al 2006;Schröder et al 2008), defocussing-based approaches (Pereira et al 2000(Pereira et al , 2007Willert and Gharib 1992), scanning-light-sheet methods (Burgmann et al 2008;Hoyer et al 2005;Brücker 1995) and absorption based methods (Jehle and Jähne 2008;Berthe et al 2010;Voss et al 2012). …”

Section: Small-scale Measurements Techniquesmentioning

confidence: 99%

“…Absorption based methods do not need this additional step, which may introduce further sources of errors. They encode the depth below the interface by light absorption in the dyed water body (Jehle and Jähne 2008;Berthe et al 2010;Voss et al 2012). Recently, an approach was presented for using one single plenoptic camera for assessing v3D3C flows .…”

Section: Small-scale Measurements Techniquesmentioning

confidence: 99%

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Transfer Across the Air-Sea Interface

Garbe

Rutgersson

Boutin

et al. 2013

Springer Earth System Sciences

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The efficiency of transfer of gases and particles across the air-sea interface is controlled by several physical, biological and chemical processes in the atmosphere and water which are described here (including waves, large-and small-scale turbulence, bubbles, sea spray, rain and surface films). For a deeper understanding of relevant transport mechanisms, several models have been developed, ranging from conceptual models to numerical models. Most frequently the transfer is described by various functional dependencies of the wind speed, but more detailed descriptions need additional information. The study of gas transfer mechanisms uses a variety of experimental methods ranging from laboratory studies to carbon budgets, mass balance methods, micrometeorological techniques and thermographic techniques. Different methods resolve the transfer at different scales of time and space; this is important to take into account when comparing different results. Air-sea transfer is relevant in a wide range of applications, for example, local and regional fluxes, global models, remote sensing and computations of global inventories. The sensitivity of global models to the description of transfer velocity is limited; it is however likely that the formulations are more important when the resolution increases and other processes in models are improved. For global flux estimates using inventories or remote sensing products the accuracy of the transfer formulation as well as the accuracy of the wind field is crucial. IntroductionThe transfer of gases and particles across the air-sea interface depends not only on the concentration difference between the water and the air, but also on the efficiency of the transfer process. The efficiency of the transfer is controlled by complex interaction of a variety of processes in the air and in the water near the interface. Here we treat both gases and particles since the transfer, to some extent, is governed by similar mechanisms. Studies of transfer across the air-sea interface include a variety of methods and techniques ranging from laboratory studies, modeling and large-scale field studies. Various methods reach somewhat different conclusions, due to representation of different

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Section: Small-scale Measurements Techniquesmentioning

confidence: 99%

Section: Small-scale Measurements Techniquesmentioning

confidence: 99%

Transfer Across the Air-Sea Interface

Garbe

Rutgersson

Boutin

et al. 2013

Springer Earth System Sciences

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“…The factor 2 is due to the fact that light has to traverse the distance of the particle below the surface once to it and once back. This technique can be extended to a measurement with incident light of two wavelengths with the benefit of independence of particle sizes, since only ratios of intensities are considered [14].…”

Section: Exponential Brightness Changementioning

confidence: 99%

“…On smaller scales, the exponential decay can be used when light is attenuated due to Lambert-Beer's law. One application will be presented in Section 4.1 and more detailed in [14]. Here, light of particles is attenuated by a special dye in the fluid.…”

Section: Exponential Brightness Changementioning

confidence: 99%

Spatiotemporal Image Analysis for Fluid Flow Measurements

Garbe

Kondermann

Jehle

et al. 2009

Notes on Numerical Fluid Mechanics and Multidisciplinary Design

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Abstract. In this chapter, a framework will be presented for measuring and modeling transport processes using novel visualization techniques and extended optical flow techniques for digital image sequence analysis. In this way, parameters besides the 2-D xy velocity components can be extracted concurrently from the acquired 2-D image sequences, such as wall shear rates and momentum transport close to boundaries, diffusion coefficients, and depth z in addition to the z velocity components. Depending on the application, particularly the temporal regularization can be enhanced, leading to stabilization of results and reduction of spatial regularization. This is frequently of high importance for flows close to boundaries. Results from applications will be presented from the fields of environmental and life sciences as well as from engineering.

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“…Other PIV-based techniques have been adapted to the measurement of free surface using an extension of the synthetic Schlieren method [12]. Alternative, non correlation-based techniques have been applied to the measurement of both shape and velocity of free surface flows [2], or to the 3D tracking of particles near a free surface [10], while a number of developments mainly focus on the measurement of the sole free surface [17,19,6].…”

Section: Introductionmentioning

confidence: 99%

Stereoscopic measurement of free surface flows

Chatellier

Jarny

Gibouin

et al. 2010

EPJ Web of Conferences

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Abstract. The present paper adresses the problem of combined three-dimensionnal measurements of shape and velocity of moving free surfaces. A measurement method based on the cross-correlation of image pairs obtained from a calibrated stereoscopic vision system is presented. The underlying concept of the method consists in the generation of parametric shape and displacement forms which are directly projected on the camera models. This procedure is then integrated in an iterative optimization process so that elevation, orientation, curvature and displacement of each surface subset are accurately estimated. Application is made on inclined plane flows of complex non-Newtonian fluids as an alternative to conventionnal rheometric devices.

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A novel method for three-dimensional three-component analysis of flows close to free water surfaces

Cited by 9 publications

References 16 publications

Transfer Across the Air-Sea Interface

Transfer Across the Air-Sea Interface

Spatiotemporal Image Analysis for Fluid Flow Measurements

Stereoscopic measurement of free surface flows

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