| Issue |
EPJ Web Conf.
Volume 143, 2017
EFM16 – Experimental Fluid Mechanics 2016
|
|
|---|---|---|
| Article Number | 02054 | |
| Number of page(s) | 5 | |
| Section | Contributions | |
| DOI | https://doi.org/10.1051/epjconf/201714302054 | |
| Published online | 12 May 2017 | |
https://doi.org/10.1051/epjconf/201714302054
Experimental investigation of cavitation induced air release
1 Ruhr University Bochum, Chair of Process Technology, Universitätsstr. 150, 44801 Bochum, Germany
2 Ruhr University Bochum, Chair of Particle Technology, Universitätsstr. 150, 44801 Bochum, Germany
3 Ruhr University Bochum, Chair of Hydraulic Fluid Machinery, Universitätsstr. 150, 44801 Bochum, Germany
* Corresponding author: kowalski@vtp.rub.de
Published online: 12 May 2017
Variations in cross-sectional areas may lead to pressure drops below a critical value, such that cavitation and air release are provoked in hydraulic systems. Due to a relatively slow dissolution of gas bubbles, the performance of hydraulic systems will be affected on long time scales by the gas phase. Therefore predictions of air production rates are desirable to describe the system characteristics. Existing investigations on generic geometries such as micro-orifice flows show an outgassing process due to hydrodynamic cavitation which takes place on time scales far shorter than diffusion processes. The aim of the present investigation is to find a correlation between global, hydrodynamic flow characteristics and cavitation induced undissolved gas fractions generated behind generic flow constrictions such as an orifice or venturi tube. Experimental investigations are realised in a cavitation channel that enables an independent adjustment of the pressure level upstream and downstream of the orifice. Released air fractions are determined by means of shadowgraphy imaging. First results indicate that an increased cavitation activity leads to a rapid increase in undissolved gas volume only in the choking regime. The frequency distribution of generated gas bubble size seems to depend only indirectly on the cavitation intensity driven by an increase of downstream coalescence events due to a more densely populated bubbly flow.
© The Authors, published by EDP Sciences, 2017
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.