Study of Supersonic Gas Flow through Nozzle by Plastic Deformation

1952 ◽  
Vol 7 (4) ◽  
pp. 431-432
Author(s):  
Nobuo Inoue
Author(s):  
Marcel Escudier

External supersonic gas flow in which changes in the fluid and flow properties are brought about by direction change is analysed in this chapter. In addition, it is shown that flow over a corner between two flat surfaces resulted in an oblique shockwave if the angle between the two surfaces is less than 180° (a concave corner). The analysis of flow through an oblique shockwave is based upon the superposition of the flowfield for a normal shock onto a uniform flow parallel to the shock. It is also shown that both weak and strong oblique shocks can occur. For an angle in excess of 180° (a convex corner), the flow is turned through an isentropic Prandtl-Meyer expansion fan. Analysis of a Prandtl-Meyer expansion fan starts from consideration of an infinitesimal flow deflection through a Mach wave.


2007 ◽  
Vol 561-565 ◽  
pp. 981-984 ◽  
Author(s):  
Naotake Niwa ◽  
Atsushi Yumoto ◽  
Takahisa Yamamoto ◽  
Fujio Hiroki ◽  
Ichiro Shiota

Recently, requirements for structural materials become increasingly severe. A coating is one of the most promising methods to achieve the requirements. However, conventional coating processes generally have technical problems. We apply Supersonic Free-Jet PVD (SFJ-PVD) to coating. The SFJ-PVD is a technique to deposit nanoparticles with supersonic gas flow and to form a thick coating film without a crack or a void. This method is composed of “gas evaporation” and “vacuum deposition”. In a gas evaporation chamber, a source material is evaporated to form nanoparticles in an inert gas atmosphere. The nanoparticles are then carried to a substrate in a deposition chamber with an inert gas flow through a transfer pipe. The gas flow is generated by the pressure difference between the chambers and accelerated through a supersonic nozzle. With SFJPVD, We obtain uniform several hundreds micron meter-thick, high-density coatings.


2018 ◽  
Vol 49 (4) ◽  
pp. 415-427
Author(s):  
Igor Ivanovich Lipatov ◽  
Vladimir Yakovlevich Neiland

2020 ◽  
Vol 58 (1) ◽  
pp. 30-43
Author(s):  
N.D. Yakimov ◽  
◽  
A.I. Khafizova ◽  
N.D. Chichirova ◽  
O.S. Dmitrieva ◽  
...  
Keyword(s):  
Gas Flow ◽  

1975 ◽  
Vol 40 (11) ◽  
pp. 3315-3318 ◽  
Author(s):  
M. Rylek ◽  
F. Kaštánek ◽  
L. Nývlt ◽  
J. Kratochvíl
Keyword(s):  
Gas Flow ◽  

2021 ◽  
Vol 11 (4) ◽  
pp. 1936
Author(s):  
Abdel-Hakim Bouzid

The accurate prediction of liquid leak rates in packing seals is an important step in the design of stuffing boxes, in order to comply with environmental protection laws and health and safety regulations regarding the release of toxic substances or fugitive emissions, such as those implemented by the Environmental Protection Agency (EPA) and the Technische Anleitung zur Reinhaltung der Luft (TA Luft). Most recent studies conducted on seals have concentrated on the prediction of gas flow, with little to no effort put toward predicting liquid flow. As a result, there is a need to simulate liquid flow through sealing materials in order to predict leakage into the outer boundary. Modelling of liquid flow through porous packing materials was addressed in this work. Characterization of their porous structure was determined to be a key parameter in the prediction of liquid flow through packing materials; the relationship between gland stress and leak rate was also acknowledged. The proposed methodology started by conducting experimental leak measurements with helium gas to characterize the number and size of capillaries. Liquid leak tests with water and kerosene were then conducted in order to validate the predictions. This study showed that liquid leak rates in packed stuffing boxes could be predicted with reasonable accuracy for low gland stresses. It was found that internal pressure and compression stress had an effect on leakage, as did the thickness change and the type of fluid. The measured leak rates were in the range of 0.062 to 5.7 mg/s for gases and 0.0013 and 5.5 mg/s for liquids.


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