Stresses that occur during nonstationary perturbation of a noncircular cylindrical cavity surface

1984 ◽  
Vol 20 (9) ◽  
pp. 806-813
Author(s):  
Yu. K. Rubtsov
Keyword(s):  
Cylindrical Cavity ◽  
Cavity Surface ◽  
Nonstationary Perturbation ◽  
Noncircular Cylindrical Cavity

Jet emerging from an annular nozzle and impinging onto cylindrical cavity: Effect of jet velocity on flow structure and heat transfer rates

2008 ◽  
Vol 222 (6) ◽  
pp. 1021-1031 ◽  
Author(s):  
S Z Shuja ◽  
B S Yilbas ◽  
S M A Khan
Keyword(s):  
Heat Transfer ◽  
Flow Structure ◽  
Cylindrical Cavity ◽  
Substrate Material ◽  
Working Fluid ◽  
Cavity Surface ◽  
Annular Nozzle ◽  
Transfer Rates ◽  
Jet Velocity

In laser gas assisting processes, nozzles are used to accelerate the impinging gas and attain a proper flow structure to improve the quality of the end product. In this study, the jet emerging from an annular nozzle and impinging onto a cylindrical cavity is considered. The effects of jet velocity at nozzle exit onto the flow structure in the region of the cavity and heat transfer rates from the cavity surface are examined. To resemble the laser-produced cavity, the cavity wall temperature is kept elevated (almost the melting temperature of the substrate material). Reynolds stress turbulence model is exploited to account for the turbulence. In the simulations, four jet velocities, two outer angles of the annular nozzle, and two depths of the cylindrical cavity are employed while air is used for the working fluid. It is found that jet velocity has a significant effect on the heat transfer rates and skin friction, which is more pronounced with increasing cavity depths.

Stress and Deformation Fields Around a Cylindrical Cavity Embedded in a Pressure-Sensitive Elastoplastic Medium

1998 ◽  
Vol 65 (2) ◽  
pp. 374-379 ◽  
Author(s):  
I. D. R. Bradford ◽  
D. Durban
Keyword(s):  
Cylindrical Cavity ◽  
Coupled System ◽  
Small Strain ◽  
Cavity Surface ◽  
Radial Coordinate ◽  
Fourier Cosine ◽  
Cosine Series ◽  
Pressure Sensitive ◽  
Fourier Cosine Series ◽  
Stress And Deformation

The problem of an internally pressurized cylindrical cavity under remote nonequibiaxial compression is examined within the framework of small strain theory. The cavity is embedded in a medium with a pressure-sensitive elastoplastic, strain-hardening and nonassociative response. The stress and deformation fields around the cavity are derived using a Drucker-Prager type deformation theory under the assumption of plane strain. The symmetry conditions allow the solution to be expanded as a Fourier cosine series in the circumferential direction. The Fourier coefficients are functions of the radial coordinate and are governed by a coupled system of ordinary differential equations. Numerical examples illustrate the evolution of the elastoplastic interface, together with the variation in both the stress concentration factor and the displacements at the cavity surface, due to increasing remote load.

scholarly journals Scattering of Surface Waves by a Three-Dimensional Cavity of Arbitrary Shape: Analytical and Experimental Studies

2019 ◽  
Vol 9 (24) ◽  
pp. 5459 ◽  
Author(s):  
Jaesun Lee ◽  
VanTrung Ngo ◽  
Haidang Phan ◽  
TruongGiang Nguyen ◽  
Duy Kien Dao ◽  
...  
Keyword(s):  
Surface Waves ◽  
Cylindrical Cavity ◽  
Arbitrary Shape ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Scattered Wave ◽  
Ultrasonic Pulse ◽  
Elastic Half Space ◽  
Cavity Surface ◽  
Vertical Displacements

The scattering of surface waves by a three-dimensional shallow cavity of arbitrary shape at the surface of a homogenous, isotropic, linearly elastic half-space is theoretically investigated. A novel analytical approach based on a reciprocity consideration is introduced in this article to determine the particle displacements of the scattered wave field generated by the interaction between the surface waves and the cavity. In the usual manner, the scattered field was shown to be equivalent to the radiation from the distribution of tractions, calculated from the incident wave, on the surface of the cavity. The radiation of surface waves subjected to the computed tractions applied at a single location was found using reciprocity theorems. The field scattered by the cavity was subsequently obtained from the superposition of displacements due to all the forces applied on the cavity surface. Solutions for the scattering of surface waves by a spherical, a circular cylindrical (coin-shaped) and a square cylindrical cavity are presented in detail. We here derive the closed-form expressions of the displacement amplitudes, which represent the far-field scattered waves produced by each of the cavities. An experimental setup using the ultrasonic pulse-echo technique was then carried out to record the scattered echoes of surface waves from these cavities in order to provide practical validation of the analytical findings. The vertical displacements measured at a significant distance of about twenty-five wavelengths from the cavities of the same width and different depth were compared with the corresponding theoretical predictions. The comparisons show excellent agreement for the case of a spherical cavity and good agreement in the cases of a circular and a cylindrical cavity in terms of trends and magnitudes. It is followed by a discussion on the results of the comparison and the limitations of the proposed approach regarding the degree of smoothness and the size of cavity.

Type II W, interband cascade and vertical-cavity surface-emitting mid-IR lasers

1998 ◽  
Vol 145 (5) ◽  
pp. 275-280 ◽  
Author(s):  
J.R. Meyer ◽  
D. Zhang ◽  
W.W. Bewley ◽  
C.L. Felix ◽  
L. Goldberg ◽  
...  
Keyword(s):  
Cavity Surface ◽  
Type Ii ◽  
Vertical Cavity Surface ◽  
Vertical Cavity

Recent developments in the area of vertical cavity surface emitting lasers

1999 ◽  
Vol 09 (PR2) ◽  
pp. Pr2-3 ◽  
Author(s):  
J. Jacquet ◽  
P. Salet ◽  
A. Plais ◽  
F. Brillouet ◽  
E. Derouin ◽  
...  
Keyword(s):  
Cavity Surface ◽  
Surface Emitting Lasers ◽  
Recent Developments ◽  
Vertical Cavity Surface ◽  
Emitting Lasers ◽  
Vertical Cavity
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