A transonic small-disturbance model for the propagation of weak shock waves in heterogeneous gases

2001 ◽  
Vol 429 ◽  
pp. 255-280 ◽  
Author(s):  
THOMAS E. GIDDINGS ◽  
ZVI RUSAK ◽  
JACOB FISH
Keyword(s):  
Shock Waves ◽  
Heterogeneous Media ◽  
Weak Shock ◽  
Small Disturbance ◽  
Gaseous Media ◽  
The Media ◽  
Observed Behaviour ◽  
Disturbance Model ◽  
Interaction Phenomena ◽  
Good Agreement

The interaction of weak shock waves with small heterogeneities in gaseous media is studied. It is first shown that various linear theories proposed for this problem lead to pathological breakdowns or singularities in the solution near the wavefront and necessarily fail to describe this interaction. Then, a nonlinear small-disturbance model is developed. The nonlinear theory is uniformly valid and accounts for the competition between the near-sonic speed of the wavefront and the small variations of vorticity and sound speed in the heterogeneous media. This model is an extension of the transonic small-disturbance problem, with additional terms accounting for slight variations in the media. The model is used to analyse the propagation of the sonic-boom shock wave through the turbulent atmospheric boundary layer. It is found that, in this instance, the nonlinear model accounts for the observed behaviour. Various deterministic examples of interaction phenomena demonstrate good agreement with available experimental data and explain the main observed phenomena in Crow (1969).

scholarly journals Utilizing Curvilinear Grid for 2D Wave Field Simulation Heterogeneous Media with Topography

2020 ◽  
Vol 18 (3) ◽  
pp. 81-95
Author(s):  
Pavel A. Titov
Keyword(s):  
Difference Scheme ◽  
Wave Field ◽  
Heterogeneous Media ◽  
Practical Interest ◽  
Good Alternative ◽  
Curvilinear Grid ◽  
2D System ◽  
The Media ◽  
The Subject ◽  
Good Agreement

The main practical interest of geophysics is the restoration of the structure of the medium. So one can understand whether there are hydrocarbon reservoirs at depth. Studying the structure of the medium by taking numerous samples and drilling wells is a very financially and time-consuming task. Therefore, the use of mathematical modeling seems to be a good alternative. If the calculations show a result similar to the initial data of the medium, then such algorithm for restoring the medium can be applied new regions. Verification of the algorithm should be carried out on real structures of the media, but real wave field data are not provided, since they are often the subject of trade secrets. In this case, the result of this work comes to the rescue. Numerical simulation is widely used in studying the processes of wave field propagation in various complex media. One way is to discrete the domain for which the simulation is being performed, and to construct a difference scheme for further numerical implementation. This work involves the construction of a mesh with curved quadrangles, which allows good agreement with the topography of the surface. A parallel algorithm of numerical modeling based on the numerical solution of a linear 2D system of elasticity theory written in displacements using a curvilinear mesh and an explicit difference scheme is proposed. The simulation results are presented. The calculations were carried out using the resources of the SSCC SB RAS.

Experimental study of heat transfer in the boundary layer of a flat plate with the impact of weak shock waves on the leading edge

2020 ◽  
Author(s):  
V. L. Kocharin ◽  
A. A. Yatskikh ◽  
D. S. Prishchepova ◽  
A. V. Panina ◽  
Yu. G. Yermolaev ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Experimental Study ◽  
Shock Waves ◽  
Flat Plate ◽  
Leading Edge ◽  
Weak Shock ◽  
The Impact

Acoustic Emission Monitoring of Leaks in Pipes for Transport of Liquid and Gaseous Media: A Model Experiment

2006 ◽  
Vol 13-14 ◽  
pp. 351-356 ◽  
Author(s):  
Andreas J. Brunner ◽  
Michel Barbezat
Keyword(s):  
Acoustic Emission ◽  
Model Experiment ◽  
Structural Integrity ◽  
Fiber Composite ◽  
Leak Testing ◽  
Pipe Segment ◽  
Potential Applications ◽  
Gaseous Media ◽  
The Media ◽  
Ae Signals

In order to explore potential applications for Active Fiber Composite (AFC) elements made from piezoelectric fibers for structural integrity monitoring, a model experiment for leak testing on pipe segments has been designed. A pipe segment made of aluminum with a diameter of 60 mm has been operated with gaseous (compressed air) and liquid media (water) for a range of operating pressures (between about 5 and 8 bar). Artificial leaks of various sizes (diameter) have been introduced. In the preliminary experiments presented here, commercial Acoustic Emission (AE) sensors have been used instead of the AFC elements. AE sensors mounted on waveguides in three different locations have monitored the flow of the media with and without leaks. AE signals and AE waveforms have been recorded and analysed for media flow with pressures ranging from about 5 to about 8 bar. The experiments to date show distinct differences in the FFT spectra depending on whether a leak is present or not.

Effects of Viscosity on Steady Reflection of Weak Shock Waves

2008 ◽  
Author(s):  
Mikhail Ivanov ◽  
Yevgeny Bondar ◽  
Dmitry Khotyanovsky ◽  
Alexey Kudryavtsev ◽  
Georgiy Shoev
Keyword(s):  
Shock Waves ◽  
Weak Shock

Simulation of Sphere’s Motion Induced by Shock Waves

2012 ◽  
Vol 134 (10) ◽  
Author(s):  
Dan Igra ◽  
Ozer Igra ◽  
Lazhar Houas ◽  
Georges Jourdan
Keyword(s):  
Shock Waves ◽  
Drag Coefficient ◽  
Drag Force ◽  
Stationary Flow ◽  
Experimental Results ◽  
Experimental Findings ◽  
Sphere Drag ◽  
Simulation Scheme ◽  
Good Agreement

Simulations of experimental results appearing in Jourdan et al. (2007, “Drag Coefficient of a Sphere in a Non-Stationary Flow: New Results,”Proc. R. Soc. London, Ser. A, 463, pp. 3323–3345) regarding acceleration of a sphere by the postshock flow were conducted in order to find the contribution of the various parameters affecting the sphere drag force. Based on the good agreement found between present simulations and experimental findings, it is concluded that the proposed simulation scheme could safely be used for evaluating the sphere’s motion in the postshock flow.

On the propagation of weak shock waves in compressible thermohyperelastic solids

2017 ◽  
Vol 229 (1) ◽  
pp. 87-97 ◽  
Author(s):  
Hocine Bechir ◽  
Abdelhakim Benslimane
Keyword(s):  
Shock Waves ◽  
Weak Shock
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