Active piston technique to optimize the chamber pressure in two-stage light-gas guns

2006 ◽  
Vol 33 (1-12) ◽  
pp. 592-604 ◽  
Author(s):  
D. Pavarin ◽  
A. Francesconi ◽  
F. Niero ◽  
F. Angrilli
Keyword(s):  
Chamber Pressure ◽  
Two Stage ◽  
Gas Guns

scholarly journals Performance and Modeling of a Two-Stage Light Gas Gun Driven by Gaseous Detonation

2020 ◽  
Vol 10 (12) ◽  
pp. 4383
Author(s):  
Weiqi Tang ◽  
Qiu Wang ◽  
Bingchen Wei ◽  
Jiwei Li ◽  
Jinping Li ◽  
...  
Keyword(s):  
Tube Wall ◽  
Numerical Approach ◽  
Operating Conditions ◽  
Gaseous Detonation ◽  
Two Stage ◽  
Piston Velocity ◽  
Gas Gun ◽  
Small Influence ◽  
Improved Model ◽  
Gas Guns

A two-stage light gas gun driven by gaseous detonation was newly constructed, which can make up for the disadvantages of the insufficient driving capability of high-pressure gas and the constraints of gunpowder. The performance of the gas gun was investigated through experiments and a quasi-one-dimensional modeling of it was also developed and described in detail. The model accounts for the friction and heat transfer to the tube wall for gases by adding a source term. An improved model has been established to consider the inertial loads in the piston or projectile and model the friction force with the tube wall. Besides, the effects of pump tube pressure on the performance of the gas gun are also investigated numerically. Simulations of the pressure histories in the pump tube and the piston and projectile velocities were conducted. A good agreement was observed between the computational predictions and experimental results. The results showed that the friction between the piston and wall had only small influence on the piston velocity. The proposed numerical approach is suitable for the development of two-stage light gas guns and tests of the operating conditions.

618 Measurement of Delay Time from Propellant Ignition to Projectile Launch in Two-Stage Light Gas Guns for Counter Impact

2005 ◽  
Vol 2005.58 (0) ◽  
pp. 237-238
Author(s):  
Yasuhiro AKAHOSHI ◽  
Junichi KITAGAWA ◽  
Takao KOURA ◽  
Eiji MATSUDA ◽  
Masayoshi TADAOKA ◽  
...  
Keyword(s):  
Delay Time ◽  
Two Stage ◽  
Gas Guns

A special design condition to increase the performance of two-stage light-gas guns

2008 ◽  
Vol 35 (12) ◽  
pp. 1510-1515 ◽  
Author(s):  
A. Francesconi ◽  
D. Pavarin ◽  
A. Bettella ◽  
F. Angrilli
Keyword(s):  
Special Design ◽  
Two Stage ◽  
Gas Guns

scholarly journals A gas-loading system for LANL two-stage gas guns

2015 ◽  
Author(s):  
Lloyd Lee Gibson ◽  
Brian Douglas Bartram ◽  
Dana Mcgraw Dattelbaum ◽  
John Michael Lang ◽  
John Scott Morris
Keyword(s):  
Two Stage ◽  
Loading System ◽  
Gas Guns

scholarly journals A gas-loading system for LANL two-stage gas guns

2017 ◽  
Author(s):  
L. L. Gibson ◽  
B. D. Bartram ◽  
D. M. Dattelbaum ◽  
J. M. Lang ◽  
J. S. Morris
Keyword(s):  
Two Stage ◽  
Loading System ◽  
Gas Guns

scholarly journals QUICKGUN: An algorithm for estimating the performance of two-stage light gas guns

1990 ◽  
Author(s):  
S.L. Milora ◽  
S.K. Combs ◽  
M.J. Gouge ◽  
R.W. Kincaid
Keyword(s):  
Two Stage ◽  
Gas Guns

Residual Gas Reaction in the Electron Microscope: II The Design of a Gas-Control Chamber for Quantitative Observations

1969 ◽  
Vol 27 ◽  
pp. 82-83
Author(s):  
Chester J. Calbick ◽  
Richard E. Hartman
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Local Environment ◽  
Chamber Pressure ◽  
Objective Lens ◽  
Ion Pump ◽  
Quantitative Studies ◽  
Precise Knowledge ◽  
Differential Pumping ◽  
And Control

Quantitative studies of the phenomenon associated with reactions induced by the electron beam between specimens and gases present in the electron microscope require precise knowledge and control of the local environment experienced by the portion of the specimen in the electron beam. Because of outgassing phenomena, the environment at the irradiated portion of the specimen is very different from that in any place where gas pressures and compositions can be measured. We have found that differential pumping of the specimen chamber by a 4" Orb-Ion pump, following roughing by a zeolite sorption pump, can produce a specimen-chamber pressure 100- to 1000-fold less than that in the region below the objective lens.

Studies of the scanning ion beam sputter-cleaned MgO crystal surface by scanning reflection electron microscopy

1987 ◽  
Vol 45 ◽  
pp. 144-145
Author(s):  
H.-J. Ou ◽  
J. M. Cowley ◽  
A. A. Higgs
Keyword(s):  
Crystal Surface ◽  
Ion Beam ◽  
Carbon Film ◽  
Surface Region ◽  
Bulk Sample ◽  
Chamber Pressure ◽  
Specimen Preparation ◽  
Detailed Surface ◽  
Gate Control ◽  
Reflection Electron Microscopy

A scanning ion gun system has been installed on the specimen preparation chamber (pressure ∼5xl0-8 torr) of the VG-HB5 STEM microscope. By using the specimen current imaging technique, it is possible to use an ion beam to sputter-clean the preferred surface region on a bulk sample. As shown in figure 1, the X-Y raster-gate control of the scanning unit for the Krato Mini-Beam I is used to minimize the beam raster area down to a 800μm x800μm square region. With beam energy of 2.5KeV, the MgO cleavage surface has been ion sputter-cleaned for less than 1 minute. The carbon film or other contaminant, introduced during the cleavage process in air, is mostly removed from the MgO crystal surfaces.The immediate SREM inspection of this as-cleaned MgO surface, within the adjacent STEM microscope, has revealed the detailed surface structures of atomic steps, which were difficult to observe on the as-cleaved MgO surfaces in the previous studies.

Two-stage self-seeding method for preparation of single crystals of poly(phenylene sulfide)

1989 ◽  
Vol 47 ◽  
pp. 368-369
Author(s):  
Sengshiu Chung ◽  
Peggy Cebe
Keyword(s):  
Single Crystals ◽  
High Performance ◽  
Dilute Solution ◽  
Two Stage ◽  
Annealing Behavior ◽  
High Performance Polymers ◽  
Seeding Method ◽  
Phenylene Sulfide

We are studying the crystallization and annealing behavior of high performance polymers, like poly(p-pheny1ene sulfide) PPS, and poly-(etheretherketone), PEEK. Our purpose is to determine whether PPS, which is similar in many ways to PEEK, undergoes reorganization during annealing. In an effort to address the issue of reorganization, we are studying solution grown single crystals of PPS as model materials.Observation of solution grown PPS crystals has been reported. Even from dilute solution, embrionic spherulites and aggregates were formed. We observe that these morphologies result when solutions containing uncrystallized polymer are cooled. To obtain samples of uniform single crystals, we have used two-stage self seeding and solution replacement techniques.

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