Cavitation dynamics in reflection of a compression pulse from the interface of two media

1992 ◽  
Vol 32 (4) ◽  
pp. 484-487
Author(s):  
G. I. Kanel' ◽  
A. V. Utkin
Keyword(s):  
Compression Pulse

A study of the impulse waves discharged from convergent and divergent ducts

2004 ◽  
Vol 218 (12) ◽  
pp. 1469-1479 ◽  
Author(s):  
Y H Kweon ◽  
H D Kim ◽  
T Aoki ◽  
T Setoguchi
Keyword(s):  
Shock Tube ◽  
Passive Control ◽  
Equation System ◽  
Control Device ◽  
Computational Method ◽  
Impulse Wave ◽  
Compression Pulse ◽  
Impulse Waves ◽  
Increasing Function ◽  
Straight Duct

The present study describes experimental and computational works to investigate impulse waves that are generated by discharge of a compression pulse from the exit of convergent and divergent ducts. The objective of the present study is to compare the impulse waves discharged from a straight duct with those discharged from convergent and divergent ducts. Computational analysis is performed using the axisymmetric, unsteady, inviscid, compressible, Euler equations. A second-order total variation diminishing finite difference scheme is used to solve the governing equation system. Experiment is carried out in a simple shock tube with an open end. Convergent and divergent ducts are connected to the open end of the shock tube. Initial compression pulses with different overpressures and wavelengths are made at the entrance of the convergent and divergent ducts. The present computational method predicts the measured impulse waves well. The results obtained show that for a given duct the magnitude of the impulse wave decreases as the wavelength of the initial compression pulse increases and it is a weakly increasing function of the overpressure of the initial compression pulse. Compared with a straight duct, a convergent duct leads to a weaker impulse wave, while a divergent duct causes a stronger impulse wave. It is therefore believed that the convergent duct can be a passive control device used to reduce the magnitude of the impulse wave.

EVOLUTION OF A SHORT COMPRESSION PULSE IN A HETEROGENEOUS ELASTOPLASTIC MEDIUM

2021 ◽  
Vol 62 (3) ◽  
pp. 475-483
Author(s):  
A. E. Kraus ◽  
E. I. Kraus ◽  
I. I. Shabalin ◽  
A. E. Buzyurkin
Keyword(s):  
Elastoplastic Medium ◽  
Compression Pulse

Hopkinson techniques for dynamic recovery experiments

1991 ◽  
Vol 435 (1894) ◽  
pp. 371-391 ◽  
Keyword(s):  
Bauschinger Effect ◽  
Dynamic Recovery ◽  
Single Pulse ◽  
Hopkinson Bar ◽  
Compression Pulse ◽  
Split Hopkinson Bar ◽  
Stress Reversal ◽  
Tension Recovery ◽  
Post Test ◽  
Split Hopkinson

Novel techniques are introduced to render the classical split Hopkinson bar apparatus suitable for dynamic recovery experiments, where samples can be subjected to a single pulse of pre-assigned shape and duration, and then recovered without any additional loading, for post-test characterization; i. e., techniques for fully controlled unloading in Hopkinson bar experiments. For compression dynamic recovery tests, the new design generates a compressive pulse trailed by a tensile pulse (stress reversal), travelling toward the sample. Furthermore, all subsequent pulses which reflect off the free ends of the two bars (incident and transmission) are rendered tensile, so that the sample is subjected to a single compressive pulse whose shape and duration can also be controlled. For tension recovery experiments, the new design provides for trapping the compression pulse reflected off the sample, and the tensile pulse transmitted through the sample. In addition, a sample can be subjected to compression followed by tension, and then recovered, allowing the study of, e. g. the dynamic Bauschinger effect in materials.

scholarly journals All-Fiber-Based All-Normal Dispersion Supercontinuum Source Using a Femtosecond Fiber Laser with Hollow-Core Fiber Pulse Compression

2019 ◽  
Author(s):  
Ivan Bravo Gonzalo ◽  
Thomas Vestergaard ◽  
Ole Bang
Keyword(s):  
Fiber Laser ◽  
Pulse Compression ◽  
Pulse Length ◽  
Hollow Core ◽  
Compression Pulse ◽  
Normal Dispersion ◽  
Supercontinuum Spectrum ◽  
Core Fiber ◽  
Femtosecond Fiber Laser

We develop and thoroughly characterize an all-fiber-based all-normal dispersion supercontinuum source pumped with a femtosecond fiber laser at 1036 nm using hollow-core fiber pulse compression. Pulse length, supercontinuum spectrum, and noise are measured.

scholarly journals Features of the processes of deformation of single-crystal titanium nickelide under the action of a comprehensive compression pulse

2020 ◽  
pp. 63-67
Author(s):  
M.N. Krivosheina ◽  
◽  
E.V. Tuch ◽  
Keyword(s):  
Single Crystal ◽  
Coordinate System ◽  
Titanium Nickelide ◽  
Spherical Shape ◽  
Compression Modulus ◽  
Spherical Body ◽  
Compression Pulse ◽  
Cubic Symmetry ◽  
Volume Compressibility ◽  
Crystallographic Axes

Using the example of single-crystal titanium nickelide, the importance of taking into account the volume compressibility anisotropy when calculating the processes of elastoplastic deformation in materials with cubic symmetry of elastic properties is shown. It is shown that the process of uniform volumetric deformation corresponds to the process of non-uniform stress state for materials with cubic symmetry of properties for some orientations of the calculated coordinate system relative to the directions of the main crystallographic axes. The index surface of volume compressibility (or the reciprocal of it - the compression modulus) has a non-spherical shape and is a function of Euler angles. This is shown for the first time by solving a model problem - determining the stress and strain states of a spherical body made of single-crystal titanium nickelide under the action of a comprehensive compression pulse. In the general case of orienting the calculated coordinate system relative to the directions of the main crystallographic axes, an initially spherical body of single-crystal titanium nickelide is deformed into a biaxial ellipsoid under the influence of a comprehensive compression pulse.

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