Cavitation erosion in liquid nitrogen

Matevž Dular (Author), Martin Petkovšek (Author)

Abstract

Thermodynamic effects in cavitation become significant only when the critical-point temperature is close to the operating temperature of the fluid, as in the case of cryogenic fluids. Therefore, the understanding and the prediction of the cavitation effects in such cases is crucial in many applications - for example the turbopumps for liquid hydrogen (LH2) and oxygen (LOX) in space launcher engines. The new generation of rocket engines will also feature the possibility of re-ignition while in orbit and prolonged period of operation; hence cavitation erosion is becoming an issue at the design stage of the turbo-pumps. In the study, we show measurements of cavitation erosion in liquid nitrogen (LN2), where cavitation was generated by an ultrasonic transducer. The damage was evaluated on aluminium samples. Special care was given to accurate setting of the operation point - especially the operating pressure, which defines the size of cavitation. We show that it is less aggressive than cavitation in water and that its aggressiveness cannot be described by a single fluid property (for example the most commonly used Brennen's thermodynamic parameter [sigma]), but by a combination of several (viscosity, density, vapor pressure, surface tension, thermodynamic parameter) - in the present paper we addressed this point by a simple bubble dynamics model with consideration of the thermodynamic effect to qualitatively predict the results of the measurements. Finally, we also compared performance of several other engineering materials.

Keywords

kavitacija;erozija;tekoči dušik;termodinamični vpliv;cavitation;erosion;liquid nitrogen;thermodynamic effect;

Data

Language:	English
Year of publishing:	2018
Typology:	1.01 - Original Scientific Article
Organization:	UL FS - Faculty of Mechanical Engineering
UDC:	620.193.16(045)
COBISS:	15832859
ISSN:	0043-1648
Views:	10
Downloads:	0
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	Slovenian
Secondary keywords:	kavitacija;erozija;tekoči dušik;termodinamični vpliv;
Type (COBISS):	Article
Embargo end date (OpenAIRE):	2020-01-09
Pages:	str. 111-118
Issue:	ǂVol. ǂ400/401
Chronology:	2018
DOI:	10.1016/j.wear.2018.01.003
ID:	18275608