The Mach reflection triple-point locus for internal and external conical diffraction of a moving shock wave

Shock Waves ◽  
1992 ◽  
Vol 2 (1) ◽  
pp. 5-12 ◽  
Author(s):  
Z. Y. Han ◽  
B. E. Milton ◽  
K. Takayama
Keyword(s):  
Shock Wave ◽  
Triple Point ◽  
Mach Reflection

The non-stationary hysteresis phenomenon in shock wave reflections

2013 ◽  
Vol 732 ◽  
Author(s):  
Meital Geva ◽  
Omri Ram ◽  
Oren Sadot
Keyword(s):  
Shock Wave ◽  
High Resolution ◽  
Triple Point ◽  
Convex Surface ◽  
Mach Reflection ◽  
Incident Shock ◽  
Incident Shock Wave ◽  
Concave Surface ◽  
Hysteresis Phenomenon ◽  
Regular Reflection

AbstractThe non-stationary transition from Mach to regular reflection followed by a reverse transition from regular to Mach reflection is investigated experimentally. A new experimental setup in which an incident shock wave reflects from a cylindrical concave surface followed by a cylindrical convex surface of the same radius is introduced. Unlike other studies that indicate problems in identifying the triple point, an in-house image processing program, which enables automatic detection of the triple point, is developed and presented. The experiments are performed in air having a specific heats ratio 1.4 at three different incident-shock-wave Mach numbers: 1.2, 1.3 and 1.4. The data are extracted from high-resolution schlieren images obtained by means of a fully automatically operated shock-tube system. Each experiment produces a single image. However, the high accuracy and repeatability of the control system together with the fast opening valve enables us to monitor the dynamic evolution of the shock reflections. Consequently, high-resolution results both in space and time are obtained. The credibility of the present analysis is demonstrated by comparing the first transition from Mach to regular reflection ($\mathrm{MR} \rightarrow \mathrm{RR} $) with previous single cylindrical concave surface experiments. It is found that the second transition, back to Mach reflection ($\mathrm{RR} \rightarrow \mathrm{MR} $), occurs earlier than one would expect when the shock reflects from a single cylindrical convex surface. Furthermore, the hysteresis is observed at incident-shock-wave Mach numbers smaller than those at which the dual-solution domain starts, which is the minimal value for obtaining hysteresis in steady and pseudo-steady flows. The existence of a non-stationary hysteresis phenomenon, which is different from the steady-state hysteresis phenomenon, is discovered.

Reconsideration of the So-Called von Neumann Paradox in the Reflection of a Shock Wave over a Wedge

2007 ◽  
Vol 566 ◽  
pp. 1-8
Author(s):  
Eugene I. Vasilev ◽  
Tov Elperin ◽  
Gabi Ben-Dor
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Triple Point ◽  
Mach Reflection ◽  
Weak Shock ◽  
Weak Shock Wave ◽  
Plane Shock ◽  
Von Neumann ◽  
Von Neumann Paradox ◽  
Guderley Reflection

Numerous experimental investigations on the reflection of plane shock waves over straight wedges indicated that there is a domain, frequently referred to as the weak shock wave domain, inside which the resulted wave configurations resemble the wave configuration of a Mach reflection although the classical three-shock theory does not provide an analytical solution. This paradox is known in the literature as the von Neumann paradox. While numerically investigating this paradox Colella & Henderson [1] suggested that the observed reflections were not Mach reflections but another reflection, in which the reflected wave at the triple point was not a shock wave but a compression wave. They termed them it von Neumann reflection. Consequently, based on their study there was no paradox since the three-shock theory never aimed at predicting this wave configuration. Vasilev & Kraiko [2] who numerically investigated the same phenomenon a decade later concluded that the wave configuration, inside the questionable domain, includes in addition to the three shock waves a very tiny Prandtl-Meyer expansion fan centered at the triple point. This wave configuration, which was first predicted by Guderley [3], was recently observed experimentally by Skews & Ashworth [4] who named it Guderley reflection. The entire phenomenon was re-investigated by us analytically. It has been found that there are in fact three different reflection configurations inside the weak reflection domain: • A von Neumann reflection – vNR, • A yet not named reflection – ?R, • A Guderley reflection – GR. The transition boundaries between MR, vNR, ?R and GR and their domains have been determined analytically. The reported study presents for the first time a full solution of the weak shock wave domain, which has been puzzling the scientific community for a few decades. Although the present study has been conducted in a perfect gas, it is believed that the reported various wave configurations, namely, vNR, ?R and GR, exist also in the reflection of shock waves in condensed matter.

scholarly journals Approximate Analytical Models of Shock-Wave Structure at Steady Mach Reflection

Fluids ◽  
2021 ◽  
Vol 6 (9) ◽  
pp. 305
Author(s):  
Mikhail V. Chernyshov ◽  
Karina E. Savelova ◽  
Anna S. Kapralova
Keyword(s):  
Experimental Data ◽  
Shock Wave ◽  
Comparative Analysis ◽  
Analytical Model ◽  
Mach Reflection ◽  
Supersonic Jet ◽  
Wave Structure ◽  
Analytical Models ◽  
Analytical Prediction ◽  
Shock Wave Structure

In this study, we obtain the comparative analysis of methods of quick approximate analytical prediction of Mach shock height in planar steady supersonic flows (for example, in supersonic jet flow and in narrowing channel between two wedges), that are developed since the 1980s and being actively modernized now. A new analytical model based on flow averaging downstream curved Mach shock is proposed, which seems more accurate than preceding models, comparing with numerical and experimental data.

A secondary small-scale turbulent mixing phenomenon induced by shock-wave Mach-reflection slip-stream instability

Shock Waves ◽  
2009 ◽  
pp. 1347-1352 ◽  
Author(s):  
A. Rikanati ◽  
O. Sadot ◽  
G. Ben-Dor ◽  
D. Shvarts ◽  
T. Kuribayashi ◽  
...  
Keyword(s):  
Shock Wave ◽  
Turbulent Mixing ◽  
Mach Reflection ◽  
Small Scale ◽  
Stream Instability

Mach reflection of a plane shock wave passing a mountain of 45° inclination

1986 ◽  
Vol 2 (1) ◽  
pp. 8-17
Author(s):  
Huang Wensheng ◽  
Liu Keqi ◽  
Hu Yongsheng ◽  
Li Zhinian ◽  
Li Yinfan
Keyword(s):  
Shock Wave ◽  
Mach Reflection ◽  
Plane Shock Wave ◽  
Plane Shock

Shock-Wave Mach-Reflection Slip-Stream Instability: A Secondary Small-Scale Turbulent Mixing Phenomenon

2006 ◽  
Vol 96 (17) ◽  
Author(s):  
A. Rikanati ◽  
O. Sadot ◽  
G. Ben-Dor ◽  
D. Shvarts ◽  
T. Kuribayashi ◽  
...  
Keyword(s):  
Shock Wave ◽  
Turbulent Mixing ◽  
Mach Reflection ◽  
Small Scale ◽  
Stream Instability

Triple-point trajectory of a strong spherical shock wave

AIAA Journal ◽  
1981 ◽  
Vol 19 (6) ◽  
pp. 815-817 ◽  
Author(s):  
K. Takayama ◽  
H. Sekiguchi
Keyword(s):  
Shock Wave ◽  
Triple Point ◽  
Spherical Shock Wave ◽  
Spherical Shock
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