Laser Doppler Systems

Albrecht, H.-E.; Borys, Michael; Damaschke, Nils; Tropea, Cameron

doi:10.1007/978-3-662-05165-8_7

Cited by 6 publications

(2 citation statements)

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“…One is a correction using a weighting function with the transit time of a particle in the measurement control volume (Albrecht et al. 2002). Another is a correction for the fringe distortion of the LDV.…”

Section: Methodsmentioning

confidence: 99%

Reynolds number dependence of turbulent kinetic energy and energy balance of 3-component turbulence intensity in a pipe flow

Ono,

Furuichi,

Tsuji

2023

J. Fluid Mech.

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Measurement data sets are presented for the turbulence intensity profile of three velocity components ( $u$ , $v$ and $w$ ) and turbulent kinetic energy (TKE, $k$ ) over a wide range of Reynolds numbers from $Re_\tau =990$ to 20 750 in a pipe flow. The turbulence intensity profiles of the $u$ - and $w$ -component show logarithmic behaviour, and that of the $v$ -component shows a constant region at high Reynolds numbers, $Re_\tau >10\,000$ . Furthermore, a logarithmic region is also observed in the TKE profile at $y/R=0.055\unicode{x2013}0.25$ . The Reynolds number dependences of peak values of $u$ -, $w$ -component and TKE fit to both a logarithmic law (Marusic et al., Phys. Rev. Fluids, vol. 2, 2017, 100502) and an asymptotic law (Chen and Sreenivasan, J. Fluid Mech., vol. 908, 2020, R3), within the uncertainty of measurement. The Reynolds number dependence of the bulk TKE $k^+_{bulk}$ , which is the total amount of TKE in the cross-sectional area of the pipe also fits to both laws. When the asymptotic law is applied to the $k^+_{bulk}$ , it asymptotically increases to the finite value $k^+_{bulk}=11$ as the Reynolds number increases. The contribution ratio $\langle u'^2\rangle /k$ reaches a plateau, and the value tends to be constant within $100< y^+<1000$ at $Re_\tau >10\ 000$ . Therefore, the local balance of each velocity component also indicates asymptotic behaviour. The contribution ratios are balanced in this region at high Reynolds numbers as $\langle u'^2\rangle /k\simeq 1.25$ , $\langle w'^2\rangle /k\simeq 0.5$ and $\langle v'^2\rangle /k \simeq 0.25$ .

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Section: Methodsmentioning

confidence: 99%

Reynolds number dependence of turbulent kinetic energy and energy balance of 3-component turbulence intensity in a pipe flow

Ono,

Furuichi,

Tsuji

2023

J. Fluid Mech.

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“…A repeatable, operator-independent and quantitative setup procedure has been developed in [ 50 ] in the case of a laser Doppler dual-incident-beam velocimeter in reference-beam configuration on the way to a complete characterisation of the measurement instrument. Some reference literature on waterjet velocity measurements [ 51 ] and laser Doppler techniques [ 52 ] was studied on purpose. Determining the measurement uncertainty of a self-developed instruments is a necessary step for its use in scientific studies.…”

Section: Sensors and Measurementsmentioning

confidence: 99%

A Review of Waterjet Cutting Research towards microAWJ and the Definition of the Waterjet Digital Twin

Annoni

2024

Materials

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This review paper aimed to draw the red line passing through almost 25 years of research on waterjet cutting carried out at WJ_Lab, the waterjet laboratory of the Department of Mechanical Engineering of Politecnico di Milano. The purpose was not to just historically analyse the obtained scientific results by themselves but to make them even more useful by introducing the concept of the waterjet digital twin passing through the accuracy improvements due to microAWJ. This strategy effectively creates synergy among the topics and gives the opportunity to researchers in this field to both have an example of how research in industrial manufacturing processes can be guided by scientific and industrial needs, at least from the author’s point of view, and to appreciate how it can be made useful for further improvements by introducing a powerful concept as the digital twin.

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Acoustic Characterization of Forward- and Backward-Skewed Axial Fans Under Increased Inflow Turbulence

2017

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Laser Doppler Systems

Cited by 6 publications

References 0 publications

Reynolds number dependence of turbulent kinetic energy and energy balance of 3-component turbulence intensity in a pipe flow

Reynolds number dependence of turbulent kinetic energy and energy balance of 3-component turbulence intensity in a pipe flow

A Review of Waterjet Cutting Research towards microAWJ and the Definition of the Waterjet Digital Twin

Acoustic Characterization of Forward- and Backward-Skewed Axial Fans Under Increased Inflow Turbulence

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