A new velocity estimation method using spectral identification of noise

Fischer, Stéphane; Schmitt, Philippe; Ensminger, Denis; Abda, Farès; Pallarès, Anne

doi:10.1016/j.flowmeasinst.2007.06.008

Cited by 16 publications

(8 citation statements)

References 7 publications

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“…Li et al, Jayakumar et al., and Wei et al used ultrasonic technology to measure the liquid film thickness under different flow conditions, thus proving the accuracy of ultrasonic probes in measuring liquid film thickness. The detailed measurement principles and usage of the UDV are described in the literature. − …”

Section: Experimental Systemmentioning

confidence: 99%

Effect of Structural Optimization of Scrubbing Cooling Rings on Vertical Falling Film Flow Characteristics

Huang

Wang

et al. 2022

ACS Omega

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In order to study the influence of the structural optimization of the scrubbing cooling ring in the scrubbing cooling chamber on the flow characteristics of the vertical falling film, the flow characteristics of the turbulent falling film in the rising section of the development region at different internal platform heights of the scrubbing cooling ring and a high Reynolds number were studied by FLUENT software. First, the correctness of the model was verified by the maximum error of simulation and experimental results of no more than 9.836%. Then, the distribution of liquid film thickness (δ), velocity ( V ), and turbulence intensity ( I z ) at 0° of the tube in the axial direction x = 0–500 mm were calculated and obtained when the platform height ( H ) was 0–30 mm and the liquid film Reynolds number ( Re l ) = 1.1541 × 10 4 –3.4623 × 10 4 . The results showed that δ in the entrance region increased sharply due to the “jet” effect with solid wall constraints formed by the structure of the water inlet pipe and the scrubbing cooling ring. On the contrary, the liquid film in the fully developed region showed a stable fluctuation trend due to the weakening of the “jet” effect. When H = 30 mm, the change of δ was relatively stable and the change of I z was small, indicating that this platform height is conducive to the stable and uniform distribution of the liquid film. In addition, when Re l < 1.1541 × 10 4 , the liquid film was unstable due to the low flow rate and insufficient cohesion of the liquid film, but V increased slightly. In addition, with the increase of Re l , δ did not change significantly along the axial direction, that is, the Plateau–Rayleigh hindered the growth of δ. Finally, the empirical formula for δ applicable to Re l = 1.1541 × 10 4 –3.4623 × 10 4 at the axial fixed position was fitted for the first time.

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Section: Experimental Systemmentioning

confidence: 99%

Effect of Structural Optimization of Scrubbing Cooling Rings on Vertical Falling Film Flow Characteristics

Huang

Wang

et al. 2022

ACS Omega

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“…Velocity values at sampling time and gate were rejected for low normalized backscatter, which indicated insufficient signal return from suspended particles. This also corresponded to low signal to noise ratio, and in these cases, the volume backscatter is too low for a reliable estimation of the Doppler velocity [50]. The minimum threshold for the normalized backscatter was calibrated versus observed flow depths and overtopping discharges, as described in Sections 4 and 5.…”

Section: = Max ( ) Median ( )mentioning

confidence: 99%

Non-Intrusive Measurements of Wave-Induced Flow over Dikes by Means of a Combined Ultrasound Doppler Velocimetry and Videography

Gaeta

Guerrero

Formentin

et al. 2020

Water

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The performance of non-intrusive instruments, such as acoustic profilers and cameras, to describe the wave-induced flow processes over maritime dike crest was investigated in experiments carried out at the University of Bologna. Direct and derived measurements from the acoustic probes deployed along the structure crest were discussed in relation to the observed backscatter rates. Image processing was implemented by means of clustering algorithm, in order to detect the free surface during overtopping events and characterize wave front propagation over the dike crest. UVP data were processed to indirectly derive flow depths and overtopping rates and compare them with the direct measurements in order to assess the measurement reliability and discuss their limits. Individual overtopping volume distribution as obtained by UVP data were estimated and compared with well-consolidated formulations, showing a good agreement. Finally, suggestions for an appropriate use of non-intrusive instruments to characterize a shallow, transient and aerated flow were provided, such as the control of the artificial seeding density, the use of a bi-static UVP configuration and adjustments to light exposure.

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“…They are the commercial devices with characteristics and performances similar to the fluxmeter presented during ISUD 2006 [18]. Both instruments allow multifrequency measurements with two wideband transducers emitting with a given tilt regarding to the instrument's base (see Table 1).…”

Section: Instrumentationmentioning

confidence: 99%