Transition from regular to Mach reflection of shock waves Part 1. The effect of viscosity in the pseudosteady case

1982 ◽  
Vol 123 ◽  
pp. 143-153 ◽  
Author(s):  
H. G. Hornung ◽  
J. R. Taylor
Keyword(s):  
Reynolds Number ◽  
Shock Waves ◽  
Experimental Method ◽  
Excellent Agreement ◽  
Mach Reflection ◽  
Regular Reflection ◽  
Transition Condition ◽  
Observed Behaviour

It is demonstrated experimentally that the influence of viscosity on the transition condition in pseudosteady flow is very significant. A mechanism is proposed for this effect, which explains the features of the observed behaviour. In particular, an experimental method of finding the inviscid transition condition, by extrapolation to infinite Reynolds number, gives excellent agreement with the calcwlatcd inviscid sonic criterion. It is thought that this provides the explanation for the usual persistence of regular reflection beyond the sonic: condition.

Downstream flow condition effects on the RR → MR transition of asymmetric shock waves in steady flows

2009 ◽  
Vol 620 ◽  
pp. 43-62 ◽  
Author(s):  
Z. M. HU ◽  
R. S. MYONG ◽  
M. S. KIM ◽  
T. H. CHO
Keyword(s):  
Shock Waves ◽  
Mach Reflection ◽  
Flow Structures ◽  
Steady Flows ◽  
Regular Reflection ◽  
Double Wedge ◽  
Asymmetric Reflection ◽  
Asymmetric Shock ◽  
Downstream Flow ◽  
Good Agreement

In this paper, the regular reflection (RR) to Mach reflection (MR) transition of asymmetric shock waves is theoretically studied by employing the classical two- and three-shock theories. Computations are conducted to evaluate the effects of expansion fans, which are inherent flow structures in asymmetric reflection of shock waves, on the RR → MR transition. Comparison shows good agreement among the theoretical, numerical and experimental results. Some discrepancies between experiment and theory reported in previous studies are also explained based on the present theoretical analysis. The advanced RR → MR transition triggered by a transverse wave is also discussed for the interaction of a hypersonic flow and a double-wedge-like geometry.

The reflection of asymmetric shock waves in steady flows: a numerical investigation

2002 ◽  
Vol 469 ◽  
pp. 71-87 ◽  
Author(s):  
M. S. IVANOV ◽  
G. BEN-DOR ◽  
T. ELPERIN ◽  
A. N. KUDRYAVTSEV ◽  
D. V. KHOTYANOVSKY
Keyword(s):  
Numerical Simulation ◽  
Experimental Investigation ◽  
Shock Waves ◽  
Numerical Investigation ◽  
Theoretical Study ◽  
Mach Reflection ◽  
Hysteresis Phenomenon ◽  
Steady Flows ◽  
Regular Reflection ◽  
Asymmetric Shock

The theoretical study and experimental investigation of the reflection of asymmetric shock waves in steady flows reported by Li et al. (1999) are complemented by a numerical simulation. All the findings reported in both the theoretical study and the experimental investigation were also evident in the numerical simulation. In addition to weak regular reflection and Mach reflection wave configurations, strong regular reflection and inverse-Mach reflection wave configurations were recorded numerically. The hysteresis phenomenon, which was hypothesized in the course of the theoretical study and then verified in the experimental investigation, was also observed in the numerical simulation.

Gaseous detonation propagation in a bifurcated tube

2008 ◽  
Vol 599 ◽  
pp. 81-110 ◽  
Author(s):  
C. J. WANG ◽  
S. L. XU ◽  
C. M. GUO
Keyword(s):  
Numerical Simulation ◽  
Detonation Wave ◽  
Mach Reflection ◽  
Initial Pressure ◽  
Gaseous Detonation ◽  
Recirculation Region ◽  
Horizontal Branch ◽  
Regular Reflection ◽  
Detonation Propagation ◽  
Wall Geometry

Gaseous detonation propagation in a bifurcated tube was experimentally and numerically studied for stoichiometric hydrogen and oxygen mixtures diluted with argon. Pressure detection, smoked foil recording and schlieren visualization were used in the experiments. Numerical simulation was carried out at low initial pressure (8.00kPa), based on the reactive Navier–Stokes equations in conjunction with a detailed chemical reaction model. The results show that the detonation wave is strongly disturbed by the wall geometry of the bifurcated tube and undergoes a successive process of attenuation, failure, re-initiation and the transition from regular reflection to Mach reflection. Detonation failure is attributed to the rarefaction waves from the left-hand corner by decoupling leading shock and reaction zones. Re-initiation is induced by the inert leading shock reflection on the right-hand wall in the vertical branch. The branched wall geometry has only a local effect on the detonation propagation. In the horizontal branch, the disturbed detonation wave recovers to a self-sustaining one earlier than that in the vertical branch. A critical case was found in the experiments where the disturbed detonation wave can be recovered to be self-sustaining downstream of the horizontal branch, but fails in the vertical branch, as the initial pressure drops to 2.00kPa. Numerical simulation also shows that complex vortex structures can be observed during detonation diffraction. The reflected shock breaks the vortices into pieces and its interaction with the unreacted recirculation region induces an embedded jet. In the vertical branch, owing to the strength difference at any point and the effect of chemical reactions, the Mach stem cannot be approximated as an arc. This is different from the case in non-reactive steady flow. Generally, numerical simulation qualitatively reproduces detonation attenuation, failure, re-initiation and the transition from regular reflection to Mach reflection observed in experiments.

scholarly journals Interaction between Shock Waves Travelling in the Same Direction

Fluids ◽  
2021 ◽  
Vol 6 (9) ◽  
pp. 315
Author(s):  
Pavel Bulat ◽  
Konstantin Volkov ◽  
Igor Volobuev
Keyword(s):  
Shock Waves ◽  
Contact Discontinuity ◽  
Jet Engines ◽  
Mach Stem ◽  
Regular Reflection ◽  
Reflected Shock ◽  
Different Types ◽  
Irregular Reflection

In this paper, we study the intersection (interaction) between several steady shocks traveling in the same direction. The interaction between overtaking shocks may be regular or irregular. In the case of regular reflection, the intersection of overtaking shocks leads to the formation of a resulting shock, contact discontinuity, and some reflected discontinuities. The type of discontinuity depends on the parameters of incoming shocks. At the irregular reflection, a Mach shock forms between incoming overtaking shocks. Reflected discontinuities come from the points of intersection of the Mach stem with the incoming shocks. We also consider the possible types of shockwave configurations that form both at regular and irregular interactions of several overtaking shocks. The regions of existence of overtaking shock waves with different types of reflected shock and the intensity of reflected shocks are defined. The results obtained in the study can potentially be useful for designing supersonic intakes and advanced jet engines.

Transition from regular to Mach reflection of shock waves Part 2. The steady-flow criterion

1982 ◽  
Vol 123 ◽  
pp. 155-164 ◽  
Author(s):  
H. G. Hornung ◽  
M. L. Robinson
Keyword(s):  
Shock Waves ◽  
Steady Flow ◽  
Mach Reflection ◽  
Strong Shock ◽  
Hysteresis Effect ◽  
Neumann Condition ◽  
Flow Transition ◽  
Von Neumann ◽  
Mach Numbers ◽  
Flow Criterion

It is shown experimentally that, in steady flow, transition to Mach reflection occurs at the von Neumann condition in the strong shock range (Mach numbers from 2.8 to 5). This criterion applies with both increasing and decreasing shock angle, so that the hysteresis effect predicted by Hornung, Oertel & Sandeman (1979) could not be observed. However, evidence of the effect is shown to be displayed in an unsteady experiment of Henderson & Lozzi (1979).

On the interaction between shock waves and boundary layers

1951 ◽  
Vol 47 (3) ◽  
pp. 545-553 ◽  
Author(s):  
K. Stewartson
Keyword(s):  
Boundary Layer ◽  
Shock Wave ◽  
Reynolds Number ◽  
Shock Waves ◽  
Boundary Layers ◽  
Weak Shock ◽  
Boundary Layer Separation ◽  
Weak Shock Wave ◽  
Layer Separation ◽  
Boundary Layer Equations

AbstractThe effect on the boundary-layer equations of a weak shock wave of strength ∈ has been investigated, and it is shown that ifRis the Reynolds number of the boundary layer, separation occurs when ∈ =o(R−i). The boundary-layer assumptions are then investigated and shown to be consistent. It is inferred that separation will occur if a shock wave meets a boundary and the above condition is satisfied.

Conical Mach reflection of moving shock waves, Part 2: Physical and CFD experimentation

Shock Waves ◽  
1998 ◽  
Vol 8 (2) ◽  
pp. 93-103 ◽  
Author(s):  
B.E. Milton ◽  
K. Takayama
Keyword(s):  
Shock Waves ◽  
Mach Reflection
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