Visualization and measurements of shock waves in cavitating flow

Petkovšek, Martin (avtor), Hočevar, Marko (avtor), Dular, Matevž (avtor)

Upon cavitation cloud collapse an omnidirectional shock wave is emitted. It then travels through the flow field, causing a cascade of events resulting in erosion, noise, vibration and the cavitation shedding process. Despite that the accumulated data points evidently to the presence of the shock waves, the direct measurements hardly exist - and even then, they are very expensive and time consuming to perform. In the present paper, the possibility of detecting shock waves inside cavitating flow is shown. The methodology bases on using two conventional high speed cameras. With the first one cavitating flow from a distance is observed, determining the position of the wave, while the second camera with a microscopic lens enables a close-up view to determine the number and size change of air bubbles as a shock wave passed them. By calibration and reference measurements the amplitude of the shock waves was determined. This relatively simple approach enabled the first observation of shockwaves which occur at the cavitation cloud collapse (downstream of the attached cavity). Several examples of shock wave dynamics are shown and how they influence the general cavitation cloud behaviour. Shock wave front velocities and local pressure waves caused by cloud collapse were estimated from visualization, reaching values to more than 700 m/s and over 5 MPa respectively.

• Jezik: Angleški jezik
• Ključne besede: cavitation, shock waves, high speed video, cloud collapse
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FS - Fakulteta za strojništvo
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2020
• Št. strani: 10 str.
• Številčenje: Vol. 119, art. 110215
• PID: 20.500.12556/RUL-117685
• UDK: 532.528(045)
• ISSN pri članku: 0894-1777
• DOI: 10.1016/j.expthermflusci.2020.110215
• COBISS.SI-ID: 23172099
• Datum objave v RUL: 21.07.2020

Gradivo je del revije

• Naslov: Experimental thermal and fluid science
• Skrajšan naslov: Exp. therm. fluid sci.
• Založnik: Elsevier
• ISSN: 0894-1777
• COBISS.SI-ID: 170523

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: kavitacija, udarni valovi, visokofrekvenčno snemanje, kolaps kavitacijskega oblaka