Free surface lubrication of rotating cylinders by impacting Newtonian liquid jet

Bizjan, Benjamin (author), Širok, Brane (author), Blagojevič, Marko (author)

Free surface lubrication of rotating cylinders by Newtonian liquid jets was investigated at different impingement positions, jet- and circumferential velocities. The interaction between impinging round laminar jet and rotating surface was characterised by high-speed imaging. Compared to flat surface impingement, the liquid deposition mechanism is more complex and often accompanied by phenomena such as splashing, jet deflection and formation of radial surface stripes. Liquid splashing initially develops in direct deposition regime due to hydraulic jump-induced droplet shedding, transitioning to lamella instability splash at higher Reynolds numbers. The critical Reynolds number for splash onset is of same order of magnitude as for flat surface impingement and fairly constant at low relative jet impingement angles, but increases exponentially when angle approaches 90°. Liquid film width and thickness were both determined proportional to the square root of the jet/surface velocity ratio, with respective power law models in good agreement with measured values.

• Language: English
• Keywords: free surface lubrication, hydraulic jump, lamella instability, liquid jet impingement, rotating surface, splashing
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Submitted Version
• Year: 2021
• Number of pages: Str. 439-449
• Numbering: Vol. 33, iss. 8
• PID: 20.500.12556/RUL-133021
• UDC: 621.89:532(045)
• ISSN on article: 0954-0075
• DOI: 10.1002/ls.1565
• COBISS.SI-ID: 79474691
• Publication date in RUL: 08.11.2021

Record is a part of a journal

• Title: Lubrication science
• Shortened title: Lubr. sci.
• Publisher: Leaf Coppin
• ISSN: 0954-0075
• COBISS.SI-ID: 2144539

Secondary language

• Language: Slovenian
• Keywords: prosta površina, omočenje, hidravlična nestabilnost, pljuskanje

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P2-0401
• Name: Energetsko strojništvo