Performance test of the low-pressure thin window multi-wire chamber

2014 ◽  
Vol 38 (2) ◽  
pp. 026004
Author(s):  
Jun-Wei Zhang ◽  
Chen-Gui Lu ◽  
Li-Min Duan ◽  
Long Ma ◽  
Rong-Jiang Hu ◽  
...  
Keyword(s):  
Performance Test ◽  
Low Pressure ◽  
Wire Chamber

Technical and Economic Analysis of 150MW Turbine Unit about Two Reconstruction Modes for High Back Pressure Heating

2013 ◽  
Vol 291-294 ◽  
pp. 1708-1713 ◽  
Author(s):  
Jun Zhai Duan ◽  
Wei Zheng ◽  
Xue Dong Wang ◽  
Yu Zhen Hao
Keyword(s):  
Performance Test ◽  
Heat Rate ◽  
Low Pressure ◽  
Back Pressure ◽  
Heating Condition ◽  
Pressure Condition ◽  
Lower Back ◽  
Cold Source ◽  
Technical And Economic Analysis ◽  
The One

In this paper, the characteristics of two modes of high back pressure reconstruction techniques for 150 MW reheat turbine units were researched. One was reconstruction of double back pressure and double rotors and the other was one-off reconstruction of LP cylinder. The former redesigned for lower pressure(LP) rotors for running at high back pressure, and hydraulic coupling bolts adopted to achieve the switch of low pressure rotors that run at high and lower back pressures. The one-off reconstruction of LP cylinder has achieved the switch of static and dynamic blades between high and low pressure. The two reconstruction both realized heat supply on the high back pressure condition, utilized cold source loss and increased the unit efficiency. After reconstruction, the economic index under both normal back pressure condition and high back pressure heating condition have been obtained by performance test. Under the high back pressure heating condition, the unit heat rate reaches 3700-3800kJ/kW.h, and the thermal efficiency has achieved 95-97%.

scholarly journals Coupling of a BaF2 scintillator to a TMAE photocathode and a low-pressure wire chamber

1983 ◽  
Vol 217 (1-2) ◽  
pp. 217-223 ◽  
Author(s):  
D.F. Anderson ◽  
R. Bouclier ◽  
G. Charpak ◽  
S. Majewski ◽  
G. Kneller
Keyword(s):  
Low Pressure ◽  
Wire Chamber ◽  
Pressure Wire

Numerical Study on Aeroelastic Instability for a Low-Speed Fan

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Kuen-Bae Lee ◽  
Mark Wilson ◽  
Mehdi Vahdati
Keyword(s):  
Performance Test ◽  
Numerical Study ◽  
Pressure Ratio ◽  
Low Pressure ◽  
Computational Domain ◽  
Low Speed ◽  
Acoustic Liners ◽  
Significant Difference ◽  
Fan Blade ◽  
Flutter Margin

Over recent years, engine designs have moved increasingly toward low specific thrust cycles to deliver significant specific fuel consumption (SFC) improvements. Such fan blades may be more prone to aerodynamic and aeroelastic instabilities than conventional fan blades. The aim of this paper is to analyze the flutter stability of a low-speed/low pressure ratio fan blade. By using a validated computational fluid dynamics (CFD) model (AU3D), three-dimensional unsteady simulations are performed for a modern low-speed fan rig for which extensive measured data are available. The computational domain contains a complete fan assembly with an intake duct and the downstream outlet guide vanes (OGVs), which is a whole low-pressure (LP) domain. Flutter simulations are conducted over a range of speeds to understand flutter characteristics of this blade. Only the first flap (1F) mode is considered in this work. Measured rig data obtained by using the same fan set but with two different lengths of the intake showed a significant difference in the flutter boundary for the two intakes. AU3D computations were performed for both intakes and were used to explain this difference between the two intakes, and showed that intake reflections play an important role in flutter of this blade. This observation indicates that the experiment with the long intake used for the performance test may be misleading for flutter. In the next phase of this work, two possible modifications for increasing the flutter margin of the fan blade were explored: changing the mode shape of the blade and using acoustic liners in the casing. The results show that it is possible to increase the flutter margin of the blade by either decreasing the ratio of the twisting to plunging motion in 1F mode or by introducing deep acoustic liners in the intake. The liners have to be deep enough to attenuate the flutter pressure waves and hence influence the stability. The results indicate the importance of reflection in flutter stability of the fan blade and clearly show that intake duct needs to be included in flutter study of any fan blade.

scholarly journals COUNTERACTING HIGH WINDS WITH LOW PRESSURE: DEVELOPMENT AND TESTING OF A NEW ROOF VENT SYSTEM

2011 ◽  
Vol 6 (4) ◽  
pp. 65-76
Author(s):  
Elizabeth Grant ◽  
James Jones
Keyword(s):  
High Speed ◽  
Performance Test ◽  
Ambient Pressure ◽  
Low Pressure ◽  
High Wind ◽  
System Failures ◽  
Wind Speeds ◽  
Pressure Development ◽  
Wind Events ◽  
And Performance

Roof system failures are common during high wind events. In locations subject to high wind conditions, membrane roofing systems must typically be either physically attached or fully adhered to the substrate or ballast may be added to weigh down the membrane. An alternative to these installation approaches could be to use aerodynamics principles such as the Bernoulli and Venturi effects to create a low-pressure region beneath the membrane roof that is lower than the ambient pressure and thus counteracts the uplifting force. A new omnidirectional vent has been designed and tested that takes advantage of these aerodynamics principles to induce low pressure under the membrane layer. This new vent operates with no moving parts and was tested in the high-speed stability wind tunnel at Virginia Tech to wind speeds up to 233 km/h. The results demonstrate that this new vent generates pressures lower than the ambient when subjected to high wind conditions. This paper presents the design principles and performance test results for this new roof vent system and other applications for roof vent technologies.

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