Year-end Sale % OFF 
Abstract
Till today, factors influencing the formation and collapse of densely distributed, interacting cavitation bubbles are only qualitatively understood. The aim of the present study is to investigate experimentally the influence of selected boundary conditions on the number and size distribution of cavitation bubbles created by an ultrasonic horn (sonotrode). Cavitation bubble clouds below the sonotrode were recorded by means of phase-locked shadowgraphy imaging. The time integrated number of cavitation bubbles was found to decrease exponentially with growing bubble radius. The number of bubbles was increased with growing actuation amplitude and gap width between the sonotrode tip and an opposing solid wall. Furthermore, it could be shown that the number of cavitation bubbles depends on the actuation phase. Future investigations will focus on establishing a statistical relation between the number and size distribution of cavitation bubbles in the near wall region and the resulting cavitation erosion on solid surfaces.
Highlights
Cavitation is the formation of vapor bubbles which create pressure peaks of several hundred bars during implosion
The aim of the present study is to investigate experimentally the influence of selected boundary conditions on the number and size distribution of cavitation bubbles created by an ultrasonic horn
The present study aims to gain a better understanding of the influence of the boundary conditions on the number and size distribution of cavitation bubbles created by an ultrasonic horn, on referred to as “bubble spectrum”
Summary
Cavitation is the formation of vapor bubbles which create pressure peaks of several hundred bars during implosion. No statistical evaluation of the bubble size distribution was done with respect to the actuation amplitude, phase and the boundary distance (gap) of sonotrode tip and opposite solid wall (see Figure 2). The present study aims to gain a better understanding of the influence of the boundary conditions on the number and size distribution of cavitation bubbles created by an ultrasonic horn, on referred to as “bubble spectrum” For this purpose experiments are performed for different actuation amplitudes, phases and gap widths between the actuator tip and the opposite solid wall. At 50 μm actuation amplitude (Figure 3a, c) a typical cone bubble structure (CBS) is formed below the sonotrode tip, expanding, over the whole 17 mm gap width being partially deflected sideways at the viewing window surface. The following criteria were applied for image processing: 1. Time-averaged background images without actuation were subtracted from the bubble images of each recording sequence
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
