Estimation of the leakage for compressible gases in high-speed shaft seals

KSME Journal ◽  
1988 ◽  
Vol 2 (1) ◽  
pp. 3-8 ◽  
Author(s):  
Chung Kyun Kim
Keyword(s):  
High Speed ◽  
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

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.

Development of a Bench Test Stand for High Speed Turbochargers

2008 ◽  
Author(s):  
R. Gordon Kirk ◽  
William J. Papke ◽  
James Thomas East ◽  
Tobias Mueller ◽  
Andrew Samuel Newman
Keyword(s):  
High Speed ◽  
Test Stand ◽  
Vibration Measurement ◽  
Bench Test ◽  
Initial Operation ◽  
Oil Leakage ◽  
Vibration Stability ◽  
Bearing Design ◽  
Reduce Emissions ◽  
Shaft Seals

The design of a turbocharger test stand using high pressure compressed air is discussed in this paper. The turbocharger test stand will be used mainly for bearing testing and turbocharger shaft vibration measurement. The purpose of these measurements is to discover a bearing design that will increase the vibration stability of the turbocharger and reduce the amount of oil leakage past the shaft seals. This will ultimately reduce emissions and upkeep cost. This paper summarizes the details of the design and describes the calculations performed that assure the test stand will successfully power the turbo. The initial operation of the test stand indicates the desired operating speed can be achieved for future vibration testing.

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

Vacuum System to Minimize the Specimen Contamination of High-Performance EM

1977 ◽  
Vol 35 ◽  
pp. 68-69
Author(s):  
N. Yoshimura ◽  
K. Shirota ◽  
T. Etoh
Keyword(s):  
Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
High Vacuum ◽  
Vacuum System ◽  
Pump System ◽  
Pumping System ◽  
Diffusion Pump ◽  
Almost All ◽  
Cascade Type

One of the most important requirements for a high-performance EM, especially an analytical EM using a fine beam probe, is to prevent specimen contamination by providing a clean high vacuum in the vicinity of the specimen. However, in almost all commercial EMs, the pressure in the vicinity of the specimen under observation is usually more than ten times higher than the pressure measured at the punping line. The EM column inevitably requires the use of greased Viton O-rings for fine movement, and specimens and films need to be exchanged frequently and several attachments may also be exchanged. For these reasons, a high speed pumping system, as well as a clean vacuum system, is now required. A newly developed electron microscope, the JEM-100CX features clean high vacuum in the vicinity of the specimen, realized by the use of a CASCADE type diffusion pump system which has been essentially improved over its predeces- sorD employed on the JEM-100C.

The on-line use of histogram data for high-speed correction and alignment of electron microscope images

1984 ◽  
Vol 42 ◽  
pp. 556-557
Author(s):  
William Krakow
Keyword(s):  
Power Spectrum ◽  
High Speed ◽  
Direct Memory Access ◽  
Digital Television ◽  
Contrast Transfer Function ◽  
The Past ◽  
High Resolution Tem ◽  
On Line ◽  
Correction Of Astigmatism ◽  
The Fourier Transform

In the past few years on-line digital television frame store devices coupled to computers have been employed to attempt to measure the microscope parameters of defocus and astigmatism. The ultimate goal of such tasks is to fully adjust the operating parameters of the microscope and obtain an optimum image for viewing in terms of its information content. The initial approach to this problem, for high resolution TEM imaging, was to obtain the power spectrum from the Fourier transform of an image, find the contrast transfer function oscillation maxima, and subsequently correct the image. This technique requires a fast computer, a direct memory access device and even an array processor to accomplish these tasks on limited size arrays in a few seconds per image. It is not clear that the power spectrum could be used for more than defocus correction since the correction of astigmatism is a formidable problem of pattern recognition.

Structural changes in silicon-on-insulator material during post-implantation annealing

1986 ◽  
Vol 44 ◽  
pp. 736-737
Author(s):  
C. O. Jung ◽  
S. J. Krause ◽  
S.R. Wilson
Keyword(s):  
Integrated Circuits ◽  
Oxide Layer ◽  
High Speed ◽  
Structural Changes ◽  
Device Fabrication ◽  
Silicon On Insulator ◽  
High Quality ◽  
Radiation Hardened ◽  
Post Implantation ◽  
Very High

Silicon-on-insulator (SOI) structures have excellent potential for future use in radiation hardened and high speed integrated circuits. For device fabrication in SOI material a high quality superficial Si layer above a buried oxide layer is required. Recently, Celler et al. reported that post-implantation annealing of oxygen implanted SOI at very high temperatures would eliminate virtually all defects and precipiates in the superficial Si layer. In this work we are reporting on the effect of three different post implantation annealing cycles on the structure of oxygen implanted SOI samples which were implanted under the same conditions.

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