Base pressure control by passive methods

1985 ◽  
Author(s):  
G. IUSO
Keyword(s):  
Pressure Control ◽  
Base Pressure

Base Pressure Control with Annular Ribs

2014 ◽  
Vol 31 (2) ◽  
Author(s):  
K. Vijayaraja ◽  
C. Senthilkumar ◽  
S. Elangovan ◽  
E. Rathakrishnan
Keyword(s):  
Pressure Control ◽  
Base Pressure

scholarly journals CFD analysis of convergent-divergent nozzle flow and base pressure control using micro-JETS

2018 ◽  
Vol 7 (3.29) ◽  
pp. 232 ◽  
Author(s):  
Ambareen Khan ◽  
Abdul Aabid ◽  
S A. Khan
Keyword(s):  
Numerical Study ◽  
Dynamic Control ◽  
Turbulence Models ◽  
Pressure Control ◽  
Wall Pressure ◽  
Base Pressure ◽  
Nozzle Geometry ◽  
Orifice Diameter ◽  
Two Dimensional ◽  
Planar Area

This paper presents numerical study was undertaken to identify the use of the micro-jets to regulate the pressure in the region from two-dimensional convergent-divergent (CD) Nozzle. At the exit of the divergent nozzle in the base region 1 mm of two micro-jets orifice diameter has been arranged at ninety degrees at pcd 13 mm to control base pressure. The inertia level at the inlet to suddenly expanded duct was 1.87. The micro-jets are suddenly expanded into a two-dimensional planar area ratio of 3.24. The L/D of the duct was 1, 2, 4, 5, 6, 8 and 10. The total wall pressure distribution from inlet to the outlet too was recorded. The results indicate that the micro-jets can oblige as the effective regulators of the pressure in the base area. The duct wall pressure field is not negatively affected by the dynamic control. Nozzles were operated with the NPR in the range from 3 to 11. The results show that we can fix the flow parameter which will result in the maximum gain in the base pressure, velocity and temperature. The convergent-divergent nozzle geometry has been modeled and simulated employing turbulence models: K-ε standard wall function turbulence model from the code was validated with the commercial computational fluid dynamics.   

Direct STEM ADF imaging of gold on silicon (111)

1989 ◽  
Vol 47 ◽  
pp. 472-473
Author(s):  
P. Xu ◽  
E. J. Kirkland ◽  
J. Silcox
Keyword(s):  
Film Growth ◽  
Heavy Atom ◽  
High Vacuum ◽  
Dark Field ◽  
Thin Metal Film ◽  
Base Pressure ◽  
Ultra High Vacuum ◽  
Specimen Preparation ◽  
Dark Field Imaging ◽  
Wide Range

Many studies of thin metal film growth and the formation of metal-semiconductor contacts have been performed using a wide range of experimental methods. STEM annular dark field imaging could be an important complement since it may allow direct imaging of a single heavy atom on a thin silicon substrate. This would enable studies of the local atomic arrangements and defects in the initial stage of metal silicide formation.Preliminary experiments were performed in an ultra-high vacuum VG HB501A STEM with a base pressure of 1 × 10-10 mbar. An antechamber directly attached to the microscope for specimen preparation has a base pressure of 2×l0-10 mbar. A thin single crystal membrane was fabricated by anodic etching and subsequent reactive etching. The specimen was cleaned by the Shiraki method and had a very thin oxide layer left on the surface. 5 Å of gold was deposited on the specimen at room temperature from a tungsten filament coil monitored by a quartz crystal monitor.

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