scholarly journals Cryogenic Tribology of High-Speed Bearings and Shaft Seals in Liquid Hydrogen

2011 ◽  
Vol 6 (2) ◽  
pp. 133-141
Author(s):  
Masataka Nosaka
Keyword(s):  
High Speed ◽  
Liquid Hydrogen ◽  
Shaft Seals

HIGH SPEED-HIGH TEMPERATURE SHAFT SEALS

1956 ◽  
Author(s):  
J. W. Pennington ◽  
T. C. Kuchler ◽  
E. J. Taschenberg
Keyword(s):  
High Temperature ◽  
High Speed ◽  
Shaft Seals

Stability of an Axial Thrust Self-Balancing System

2013 ◽  
Vol 135 (1) ◽  
Author(s):  
Takashi Shimura ◽  
Satoshi Kawasaki ◽  
Masaharu Uchiumi ◽  
Toshiya Kimura ◽  
Mitsuaki Hayashi ◽  
...  
Keyword(s):  
Large Amplitude ◽  
High Speed ◽  
System Analysis ◽  
Axial Direction ◽  
Radial Pressure ◽  
Liquid Hydrogen ◽  
Axial Vibration ◽  
Axial Thrust ◽  
Balance System ◽  
Excited Vibration

Rocket pumps are characterized by high speed and high delivery pressure. Therefore, balancing of axial thrust acting on the rotor assembly is one of the most important factors. To realize complete axial thrust balancing, a balance piston-type axial-thrust self-balancing system is often used in rocket pumps. This axial thrust balance system acts dynamically as if it were a mass and spring system, although there is no mechanical spring. Sometimes, large amplitude axial vibration is observed in a liquid hydrogen turbopump. Too much vibration in the axial direction causes metal-to-metal rubbing, resulting in fatal accidents of rocket turbopumps. However, the cause of the vibration has not yet been clarified. In the present study, the self-balancing system was modeled by combining the mechanical structure and the fluid system in a calculation program of one-dimensional multidomain system analysis software. Stability of the system was investigated using this program and the possibility of existence of self-excited vibration was confirmed. Effects of geometry, fluids, viscous damping, radial pressure drop in the chamber, and orifice flow coefficients on the stability of the balance piston system were examined. As a result, it was concluded that large compressibility of liquid hydrogen was the cause of the large amplitude axial vibrations. With the results of analyses, methods to stabilize the system in order to suppress the axial vibration were suggested.

Ultra-High-Speed Performance of Ball Bearings and Annular Seals in Liquid Hydrogen at Up to 3 Million DN (120,000 rpm)©

2004 ◽  
Vol 47 (1) ◽  
pp. 43-53 ◽  
Author(s):  
MASATAKA NOSAKA ◽  
SATOSHI TAKADA ◽  
MASATAKA KIKUCHI ◽  
TAKAYUKI SUDO ◽  
MAKOTO YOSHIDA
Keyword(s):  
High Speed ◽  
Liquid Hydrogen ◽  
Ball Bearings ◽  
Ultra High Speed ◽  
Speed Performance ◽  
Annular Seals

Flow Visualization and Stream Temperature Measurement of Liquid Hydrogen Line Chill Down Experiments

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Jeremy Styborski
Keyword(s):  
Temperature Measurement ◽  
High Speed ◽  
Hydrogen Transfer ◽  
Imaging System ◽  
Bubbly Flow ◽  
Stream Temperature ◽  
Liquid Hydrogen ◽  
Low Earth Orbit ◽  
High Speed Imaging ◽  
Transfer Line

A thermally representative tank-to-tank transfer line was designed and tested at SMiRF at NASA Glenn to simulate liquid hydrogen transfer from a Low Earth Orbit depot storage tank to a customer receiver tank. The line was equipped with three external skin silicon diode measurements, one internal stream temperature measurement, and a high speed imaging system to view flow profiles as the system chilled down from 250K to LH2 temperatures. Image: Two phase flow video stills correlated with temperature measurements shows the time evolution of chill down. Skin measurements indicate chill down is nearly complete within 20s due to annular flow and liquid layer along wall, but internal stream temperature doesn't bottom out until >140s due to bubbly flow. Majority of chill down is spent in annular and bubbly flow regimes. SD1-3 are successive skin diodes mounted along the transfer line.

Single-Stage High-Pressure Turbocharging

2009 ◽  
Author(s):  
Tobias Gwehenberger ◽  
Martin Thiele ◽  
Martin Seiler ◽  
Douglas Robinson
Keyword(s):  
High Pressure ◽  
High Speed ◽  
Pressure Ratio ◽  
Continuous Operation ◽  
Single Stage ◽  
Gas Treatment ◽  
Brake Mean Effective Pressure ◽  
Compressor Pressure Ratio ◽  
Component Efficiency ◽  
Shaft Seals

To meet the ever-increasing demands that will be made on engines, and especially on planned new engine generations, in the future, the power density of their turbochargers will have to be significantly increased. Raising the brake mean effective pressure, introducing Miller timing and providing support for exhaust-gas treatment all presuppose an increase in the turbo’s compressor pressure ratio while keeping the turbo unit as compact as possible. To fulfill all of these conditions with single-stage turbocharging, a new approach to future turbocharger design is needed, especially when additional expensive materials, such as titanium, are not to be used. On the compressor side, when using proven aluminum compressors, this requires additional cooling of the compressor wheels. But other turbocharger components too, such as the turbine, bearings, shaft seals and also the casings and their connections, are exposed to higher thermal and mechanical stresses as a result of the pressure ratios being far higher than those of turbochargers currently on the market. The challenge, which could also be called a balancing act, in dimensioning new turbochargers for single-stage high-pressure turbocharging with aluminum compressors is to design the components with the help of the available tools such that sufficient safety and component lifetime are achieved while performance and component efficiency are optimized. By using the available calculation tools, such as FEM or for the fluid dynamics CFD, it is now possible to achieve compressor pressure ratios of up to 5.8 in continuous operation with single-stage turbocharging while ensuring a compact turbocharger design and aluminum compressors. The paper describes how ABB Turbo Systems Ltd has successfully developed and qualified a new single-stage high-pressure turbocharger generation with radial turbine which allows compressor pressure ratios of up to 5.8 in continuous operation at 100% engine load. First successful engine tests with the new A100 radial turbocharger generation have been carried out both on medium- and on high-speed engines. The first frame sizes of the new A100 high-pressure turbocharger series have been released for market introduction, setting a significant new benchmark for turbocharging advanced diesel and gas engines.

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