On the effect of aeration on laser ranging measurements of free water surface

Bizjan, Benjamin (author), Hočevar, Marko (author), Kolbl Repinc, Sabina (author), Rak, Gašper (author)

Aerated flows pose both challenges and opportunities in the measurement of free water surface. In this study, an amplitude-modulated continuous wave scanning LIDAR device was used to measure a distance from the device sensor to the water column surface subjected to different degrees of aeration, while reference measurements were performed by high-speed imaging. Different aeration conditions were generated by variation of the air flow rate supplied to the liquid and by using perforated plates with different hole arrangements. The LIDAR device was shown to produce level readings consistently below visible water levels. The measurement error of the LIDAR method is largely determined by the volume fraction of air in water and was lowest at about 0.1 air volume fraction. The error increases linearly until a very high air volume fraction (i.e., above 0.55), while the LIDAR method also performs poorly in unaerated water. Although the measurement uncertainty of L IDAR in the range of aerated water is by at least an order of magnitude higher than in the case of measuring dry solid surfaces, the method is viable for free surface measurement under low to moderate aeration conditions that don’t produce excessive foaming.

• Language: English
• Keywords: aerated flow, free surface, laser scanning, LIDAR, non-stationary surface
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering; FGG - Faculty of Civil and Geodetic Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: 8 str.
• Numbering: Vol. 95, art. 102502
• PID: 20.500.12556/RUL-153132
• UDC: 531.717:528.8.042
• ISSN on article: 0955-5986
• DOI: 10.1016/j.flowmeasinst.2023.102502
• COBISS.SI-ID: 177070595
• Publication date in RUL: 19.12.2023

Record is a part of a journal

• Title: Flow measurement and instrumentation
• Shortened title: Flow meas. instrum.
• Publisher: Elsevier
• ISSN: 0955-5986
• COBISS.SI-ID: 169755

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.

Secondary language

• Language: Slovenian
• Keywords: aeriran tok, prosta gladina, lasersko skeniranje, LIDAR, nestacionarna gladina