Cryogenic Tribology in High-Speed Bearings and Shaft Seals of Rocket Turbopumps

Nosaka, Masataka; Kato, Takumi

doi:10.5772/55733

Cited by 15 publications

(13 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The study on cryogenic propulsion technology for liquid rocket engines is being carried out by countries and institutional agencies worldwide, such as the Titan Orbiter Polar Surveyor (TOPS) from NASA, 1 the new-generation cryogenic propulsion plan of the French Space Agency, 2 the liquid oxygen (LO 2 )/liquid hydrogen (LH 2 ) turbopumps in Japan, 3 and the research-development of the Long March 5 series with LH 2 and LO 2 as fuel in China. 4 However, the harsh working conditions in the liquid rocket engine turbopumps, such as high speed, low viscosity, cryogenic temperature, high pressure, and space-mass limitations, call for improvements of the performances of crucial parts (such as seals, bearings, axial balance disks) in the turbopumps.…”

Section: Introductionmentioning

confidence: 99%

An experimental study on the cryogenic face seal at different inlet pressures

Zhang

Zhao

et al. 2019

Proceedings of the Institution of Mechanical Engineers, Part J:

View full text Add to dashboard Cite

An experimental test system for cryogenic high-speed hydrodynamic non-contact mechanical seals is developed. Based on this system, the performances of seals under different working conditions are studied in detail in this paper. With the experimental results, the main performances of the seals (such as inlet and outlet temperatures, separated speed, face temperature, friction force, friction coefficient, leakage rate) are obtained, and the relationships of the performances with the inlet fluid pressure, the closing force and the rotational speed are discussed. The results show that the difference between the outlet and inlet temperatures decreases with increasing inlet fluid pressure. As the speed increases, the friction force varies little and remains at a constant value. The friction coefficient of the seal is approximately 0.12 and basically does not change with the speed. The leakage rate is also maintained at approximately 190 g/s. With the increase in the closing force, the friction at the seal’s face does not change greatly, which indicates that the friction at the face is always in a stable state with the seal’s closing force.

show abstract

Section: Introductionmentioning

confidence: 99%

An experimental study on the cryogenic face seal at different inlet pressures

Zhang

Zhao

et al. 2019

Proceedings of the Institution of Mechanical Engineers, Part J:

View full text Add to dashboard Cite

show abstract

“…With the test results, the axial load (or force) of the shaft in the turbopump in the larger-scale 120,000 kg liquid rocket engine can even exceed 5000 kg. In the turbopump of the cryogenic liquid rocket engine, the shaft seals are essential for reliability of the rotating shaft systems [2]. The shaft mechanical seal, also known as the shaft face seal, is used to prevent leakage of the engine fuel (such as kerosene, liquid hydrogen, UDMH) into the oxidant chamber (such as liquid oxygen) and vice versa.…”

Section: Introductionmentioning

confidence: 99%

An Experimental Test on a Cryogenic High-Speed Hydrodynamic Non-Contact Mechanical Seal

et al. 2017

View full text Add to dashboard Cite

This version is available at https://strathprints.strath.ac.uk/61655/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the Abstract The non-contact mechanical seal of a high-speed turbopump in a liquid rocket engine operates under very harsh conditions (such as rapid start-up, cryogenic, highspeed, high-pressure and low-viscosity sealing fluid). The performance of the seal is very different to the performance under normal running conditions. In this paper, for the sake of safety, an experiment is carried out with liquid nitrogen as the sealing fluid. The experimental results with liquid nitrogen are expected to provide an equivalent seal performance as would be experienced with liquid oxygen and liquid hydrogen rocket engine. The main performance parameters, including face temperatures, leakage, face friction force, and friction coefficients, are measured in the speed-up, stable, and speed-down stages. The results show that in the speed-up stage, with rapidly increasing speed, the local face temperature rises dramatically to even higher than the vaporization temperature of liquid nitrogen, and a two-phase flow phenomenon occurs. In the start-up and stable stages, the friction coefficients are 0.25 and 0.13, respectively. After the test, it was found that the wear thickness of the rotor was 0.2 mm, and serious point corrosion appeared on the surface of the stator.

show abstract

“…Heat generation of the rotating bearing W ex is calculated by Eq. (1). In this paper, an energy increase of the coolant flowing through a bearing per unit time is defined as the bearing heat generation.…”

Section: Test Bearings and The Bearing Testermentioning

confidence: 99%

“…Cryogenic fluids are often used as rocket propellants because of their excellent performance. The bearings inside a cryogenic turbopump supporting its main shaft are operated in cryogenic fluid divided from the pump's main flow as coolant [1]. Solid lubrication is used for the cryogenic bearing since oil lubrication is not possible for cryognenic condition.…”

Section: Introductionmentioning

confidence: 99%

Heat Generation in Cryogenic Turbopump Bearing

Kakudo¹,

Takada²,

Hirayama

2021

Tribology Online

View full text Add to dashboard Cite

Ball bearings on the main shaft of rocket engine turbopumps which supply cryogenic propellants to the main combustion chamber are critical elements of the entire propulsion system of a rocket. A self-lubricating ball bearing with a retainer made of glass-clothpolytetrafluoroethylene (PTFE) laminate has been used in turbopumps developed in Japan. In the operation of the turbopump, the bearing heat generation is possible to cause sudden temperature rises of bearing elements which finally result in bearing seizure. Therefore, it is important to predict the accurate bearing heat generation under various operating conditions. In this research, the bearing heat generation operated in cryogenic hydrogen was experimentally investigated under the various operating conditions where the rotational speed and the bearing coolant condition were changed. In addition, the bearing heat generation was compared with that theoretically predicted on a numerical model of mechanical losses. It was finally clarified that the bearing heat generation is influenced dominantly by the friction loss on balls and the drag loss on an inner race.

show abstract

Cryogenic Tribology in High-Speed Bearings and Shaft Seals of Rocket Turbopumps

Cited by 15 publications

References 15 publications

An experimental study on the cryogenic face seal at different inlet pressures

An experimental study on the cryogenic face seal at different inlet pressures

An Experimental Test on a Cryogenic High-Speed Hydrodynamic Non-Contact Mechanical Seal

Heat Generation in Cryogenic Turbopump Bearing

Contact Info

Product

Resources

About