Use of the Hot‐Wire Anemometer as a Triggering and Timing Device for Wave Phenomena in a Shock Tube

1955 ◽  
Vol 26 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Darshan S. Dosanjh
Keyword(s):  
Hot Wire ◽  
2021 ◽  
Vol 46 (9) ◽  
pp. 2160
Author(s):  
Caroline Winters ◽  
Timothy Haller ◽  
Sean Kearney ◽  
Philip Varghese ◽  
Kyle Lynch ◽  
...  

Shock Waves ◽  
2001 ◽  
Vol 11 (3) ◽  
pp. 189-197 ◽  
Author(s):  
G. Jourdan ◽  
L. Schwaederlé ◽  
L. Houas ◽  
J.-F. Haas ◽  
A.N. Aleshin ◽  
...  

1995 ◽  
Vol 19 (1) ◽  
pp. 29-37 ◽  
Author(s):  
G. Briassulis ◽  
A. Honkan ◽  
J. Andreopoulos ◽  
C. B. Watkins

2010 ◽  
Author(s):  
Akira Hirose ◽  
Karl E. Lonngren
Keyword(s):  

2006 ◽  
Vol 134 ◽  
pp. 783-787 ◽  
Author(s):  
S. Ouellet ◽  
D. Frost ◽  
A. Bouamoul

1972 ◽  
Vol 22 (3) ◽  
pp. 303-317 ◽  
Author(s):  
D. H. Napier ◽  
N. Subrahmanyam
Keyword(s):  

Author(s):  
S. R. Rakhmanov

In some cases, the processes of piercing or expanding pipe blanks involve the use of high-frequency active vibrations. However, due to insufficient knowledge, these processes are not widely used in the practice of seamless pipes production. In particular, the problems of increasing the efficiency of the processes of piercing or expanding a pipe blank at a piercing press using high-frequency vibrations are being solved without proper research and, as a rule, by experiments. The elaboration of modern technological processes for the production of seamless pipes using high-frequency vibrations is directly related to the choice of rational modes of metal deformation and the prediction resistance indicators of technological tools and the reliability of equipment operation. The creation of a mathematical model of the process of vibrating piercing (expansion) of an axisymmetric pipe blank at a piercing press of a pipe press facility is an actual task. A calculation scheme for the process of piercing a pipe plank has been elaborated. A dependence was obtained characterizing the speed of front of plastic deformation propagation on the speed of penetration of a vibrated axisymmetric mandrel into the pipe workpiece being pierced. The dynamic characteristics of the occurrence of wave phenomena in the metal being pierced under the influence of a vibrated tool have been determined, which significantly complements the previously known ideas about the stress-strain state of the metal in the deformation zone. The deformation fields in the zones of the disturbed region of the deformation zone were established, taking into account the high-frequency vibrations of the technological tool. It has been established that the choice of rational parameters (amplitude-frequency characteristics) of the vibration piercing process of a pipe blank results in significant increase in the efficiency of the process, the durability of the technological tool and the quality of the pierced blanks.


2002 ◽  
Vol 715 ◽  
Author(s):  
Keda Wang ◽  
Haoyue Zhang ◽  
Jian Zhang ◽  
Jessica M. Owens ◽  
Jennifer Weinberg-Wolf ◽  
...  

Abstracta-Si:H films were prepared by hot wire chemical vapor deposition. One group was deposited at a substrate temperature of Ts=250°C with varied hydrogen-dilution ratio, 0<R<10; the other group was deposited with fixed R=3 but a varied Ts from 150 to 550°C. IR, Raman and PL spectra were studied. The Raman results indicate that there is a threshold value for the microstructure transition from a- to μc-Si. The threshold is found to be R ≈ 2 at Ts = 250°C and Ts ≈ 200°C at R=3. The IR absorption of Si-H at 640 cm-1 was used to calculate the hydrogen content, CH. CH decreased monotonically when either R or Ts increased. The Si-H stretching mode contains two peaks at 2000 and 2090 cm-1. The ratio of the integral absorption peaks I2090/(I2090+I2090) showed a sudden increase at the threshold of microcrystallinity. At the same threshold, the PL features also indicate a sudden change from a- to μc-Si., i.e. the low energy PL band becomes dominant and the PL total intensity decreases. We attribute the above IR and PL changes to the contribution of microcrystallinity, especially the c-Si gain-boundaries.


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