20.500.12556/RUL-126377 Cavitation dynamics in water at elevated temperatures and in liquid nitrogen at an ultrasonic horn tip Understanding and predicting thermodynamic effects is crucial when the critical point temperature is close to the operating temperature of the fluid, like in cryogenics. Due to the extreme difficulties of experimental investigation, predicting of thermodynamic effects in cavitation often bases on data in liquids other than cryogenics. Most often used surrogate liquids are hot water or certain refrigerants, which are selected by a single fluid property, most commonly by the thermodynamic parameter ∑. The paper presents a systematic study of the cavitation dynamics in water at 20 °C, 40 °C, 60 °C, 80 °C and 100 °C and in addition in liquid nitrogen (LN2). Cavitation dynamics on a 4.8 mm (tip diameter) ultrasonic horn tip, which oscillated at 20 kHz was investigated by high-speed visualization at 300,000 frames per second (fps). Simultaneously acoustic emissions were recorded by a high frequency pressure transducer. Measurements were performed under variation of the acoustic power in a closed, insulated vessel, where pressure could be optionally set. The main purpose of the presented investigation is to determine whether hot water can act as a surrogate liquid to cryogenics. The results may implicate the future investigations and development of a new generation of rocket engines, which also feature the possibility of re-ignition while in orbit – understanding and predicting of cavitation behaviour is becoming a crucial part at the (liquid oxygen – LOX and liquid hydrogen – LH2) turbo-pump design. ultrasonic cavitation cavitation dynamics thermodynamic effects hot water liquid nitrogen thermodynamic parameters ultrazvočna kavitacija kavitacijska dinamika termodinamski učinki vroča voda tekoči dušik true false true Angleški jezik Slovenski jezik Članek v reviji 2021-04-19 14:54:42 2021-04-19 14:54:43 2022-09-05 03:54:58 0000-00-00 00:00:00 2019 0 0 Str. 1-9 art.104652 Vol. 58 Nov. 2019 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 532.528(045) 1350-4177 10.1016/j.ultsonch.2019.104652 16697883 RAZ_Petkovsek_Martin_2019.pdf RAZ_Petkovsek_Martin_2019.pdf 1 DA74C2CDCBCD44A9201A165B200C1637 702c67e4ca02449e03699ec150f5a44cb341b7bddac1a92cd147b12d02dd0315 e59ce178-a1bb-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=142304 https://www.sciencedirect.com/science/article/pii/S1350417719302056?via%3Dihub 1 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=142303 Fakulteta za strojništvo 0 0 0