A Novel “Flying-Spot” Infrared Camera for Imaging Very Fast Thermal-Wave Phenomena

Author(s):  
Y. Q. Wang ◽  
P. K. Kuo ◽  
L. D. Favro ◽  
R. L. Thomas
Author(s):  
Quan-Wen Hou ◽  
Hai-Dong Wang

The character of wave model for heat conduction is studied by numerical simulation of heat conduction in silicon heated by laser pulse. Based on the damping of the temperature peak, the penetration depth of thermal wave can be defined which gives a new division of heat conduction regime for experiments. The thermal wave is expected to be observed when the system is shorter than the penetration depth. In the thermomass model, the penetration depth is about one magnitude larger than that in CV model. Consequently, it gives a wider region to observe thermal wave phenomena.


Physics Today ◽  
1989 ◽  
Vol 42 (4) ◽  
pp. 66-69
Author(s):  
V. S. Letokhov ◽  
Vladilen S. Letokhov ◽  
A. Mandelis ◽  
Richard Lee

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

2005 ◽  
Vol 14 ◽  
pp. 337-342 ◽  
Author(s):  
M. Dolci ◽  
G. Valentini ◽  
O. Straniero ◽  
G. Di Rico ◽  
M. Ragni ◽  
...  

1983 ◽  
Vol 44 (C6) ◽  
pp. C6-519-C6-524
Author(s):  
K. R. Grice ◽  
L. J. Inglehart ◽  
L. D. Favro ◽  
P. K. Kuo ◽  
R. L. Thomas

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.


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