Cavitation Erosion and Shockwave Focusing during bubble collapse (en)

* Presenting author
Day / Time: 09.03.2023, 09:20-09:40
Room: Saal Y4
Typ: Vortrag (strukturierte Sitzung)
Abstract: Cavitation erosion is ubiquitous in many technical systems such as hydromachinery and ship propellers. The mechanism of cavitation erosion however is not sufficiently explained, and consequently there is no reliable acoustic detection technique that could distinguish between transient and erosive cavitation. We experimentally study the erosion of a single laser-induced bubble on different metallic materials using high-speed imaging combined with acoustic measurements employing high-bandwidth PVDF and optic hydrophones. To image shock wave emission during the bubble dynamics, sub-picoscond exposure times are used. Damage on the samples is already detected in-situ and studied in detail ex-situ. We show that in contrast to common wisdom the regular jet with velocities of about 100 m/s is not responsible for erosion. Instead, a collapse dynamics involving a three-dimensional shock self-focusing is responsible for cavitation erosion. We show that in this single bubble system acoustic transients in the MHz-range are characteristic to erosive cavitation.


strpos(): Passing null to parameter #1 ($haystack) of type string is deprecated

/kunden/431424_13355/webseiten/subdomains/, line 35
32.              */
33.             if (headers_sent()) {
34.                 $encoding = false;
35.             } elseif (strpos($HTTP_ACCEPT_ENCODING, 'x-gzip') !== false) {
36.                 $encoding = 'x-gzip';
37.             } elseif (strpos($HTTP_ACCEPT_ENCODING, 'gzip') !== false) {
38.                 $encoding = 'gzip';