A Short Note about the Impact Action of a Water Jet Stabilized by a Coaxial Air Stream in the Air and Underwater
| Autor: | Josef Poláček, Irena M. Hlaváčová, Martin Tyč |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Technology
Airflow submerged jet operation Near and far field pure water jet General Materials Science Surface layer Underwater coaxial air flow Jet (fluid) Microscopy QC120-168.85 Communication blasting QH201-278.5 Mechanics Breakup Engineering (General). Civil engineering (General) TK1-9971 Descriptive and experimental mechanics Environmental science Head (vessel) Electrical engineering. Electronics. Nuclear engineering Coaxial TA1-2040 jet stabilization |
| Zdroj: | Materials, Vol 14, Iss 5015, p 5015 (2021) Materials |
| ISSN: | 1996-1944 |
| Popis: | A new original method, applying a coaxial protective airflow, was tested aiming to improve the pure water jet efficiency in surface layer removal or medium hard materials cutting or blasting. The dual action of the air flow is expected: the air co-flowing the water jet with approximately the same velocity should prevent the central jet from breaking up into tiny droplets in the near field, and simultaneously, it should support jet decomposition into big parts with enough destructive potential in the far-field. A brief survey of the relevant literature dealing with the water jet instability is presented, introducing four recognized breakup regimes. An original cutting head designed to generate a waterjet surrounded by protective coaxial air flow is introduced. The submitted device is supposed to operate within the first wind-induced regime. Two types of experiments, consisting of blasting limestone bricks placed either in the air or underwater, were realized. The depths of kerfs produced with different water pressures and air overpressures were evaluated. While no substantial positive effect was recognized in the air performance, the submerged blasting of the same material under similar conditions appeared to be promising. Web of Science 14 17 art. no. 5015 |
| Databáze: | OpenAIRE |
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