scholarly journals Experimental and Numerical Investigation of the Growth of an Air/SF6 Turbulent Mixing Zone in a Shock Tube

2017 ◽  
Vol 139 (9) ◽  
Author(s):  
J. Griffond ◽  
J.-F. Haas ◽  
D. Souffland ◽  
G. Bouzgarrou ◽  
Y. Bury ◽  
...  
Keyword(s):  
Shock Wave ◽  
Shock Tube ◽  
Cross Section ◽  
Turbulent Mixing ◽  
Test Chamber ◽  
Weak Dependence ◽  
Mixing Zone ◽  
Nitrocellulose Membrane ◽  
Mesh Spacing ◽  
Zone Growth

Shock-induced mixing experiments have been conducted in a vertical shock tube of 130 mm square cross section located at ISAE. A shock wave traveling at Mach 1.2 in air hits a geometrically disturbed interface separating air and SF6, a gas five times heavier than air, filling a chamber of length L up to the end of the shock tube. Both gases are initially separated by a 0.5 μm thick nitrocellulose membrane maintained parallel to the shock front by two wire grids: an upper one with mesh spacing equal to either ms = 1.8 mm or 12.1 mm, and a lower one with a mesh spacing equal to ml = 1 mm. Weak dependence of the mixing zone growth after reshock (interaction of the mixing zone with the shock wave reflected from the top end of the test chamber) with respect to L and ms is observed despite a clear imprint of the mesh spacing ms in the schlieren images. Numerical simulations representative of these configurations are conducted: the simulations successfully replicate the experimentally observed weak dependence on L, but are unable to show the experimentally observed independence with respect to ms while matching the morphological features of the schlieren pictures.

Thickness and volume measurements of a Richtmyer–Meshkov instability-induced mixing zone in a square shock tube

1997 ◽  
Vol 349 ◽  
pp. 67-94 ◽  
Author(s):  
G. JOURDAN ◽  
L. HOUAS ◽  
J.-F. HAAS ◽  
G. BEN-DOR
Keyword(s):  
Shock Wave ◽  
Shock Tube ◽  
Cross Section ◽  
Incident Shock ◽  
Incident Shock Wave ◽  
Mixing Zone ◽  
Laser Absorption ◽  
Shock Wave Mach Number ◽  
Atwood Number ◽  
Absorption Technique

A simultaneous three-directional laser absorption technique for the study of a shock-induced Richtmyer–Meshkov instability mixing zone is reported. It is an improvement of a CO2 laser absorption technique, using three detectors during the same run, through three different directions of the test section, for the simultaneous thickness measurement of the mixing zone near the corner, near the wall and at the centre of a square-cross-section shock tube. The three-dimensional mean front and rear shapes of the mixing zone, its thickness and volume are deduced from the experimental measurements. The cases when the shock wave passes from a heavy gas to a light one, from one gas to another of similar densities and from a light gas to a heavy one, are investigated before and after the mixing zone compression by the reflected shock, for different incident shock wave Mach numbers. It is shown that the mixing zone is strongly deformed by the wall boundary layer when it becomes turbulent. Consequently, the thickness of the mixing zone is not constant along the shock tube cross-section, and the measurement of the mean volume of the mixing zone appears to be more appropriate than its mean thickness at the centre of the shock tube. The influence of the incident shock wave Mach number is also studied. When the Atwood number tends to zero, we observe a limit-like regime and the thickness, or the volume, of the mixing zone no longer varies with the incident shock wave Mach number. Furthermore, a series of experiments undertaken with an Atwood number close to zero enabled us to define a membrane-induced minimum mixing thickness, L0, depending on the initial configuration of the experiments. From the experimental data, a hypothesis about the mixing zone thickness evolution law with time is deduced on the basis of L0. The results are found to follow two very different laws depending on whether they are considered before or after the establishment of the plenary turbulent regime. However, no general trend can be determined to describe the entire phenomenon, i.e. from the initial conditions until the turbulent stage.

Structure of the turbulent mixing zone on the boundary of two gases accelerated by a shock wave

1990 ◽  
Vol 26 (3) ◽  
pp. 315-320 ◽  
Author(s):  
E. E. Meshkov ◽  
V. V. Nikiforov ◽  
A. I. Tolshmyakov
Keyword(s):  
Shock Wave ◽  
Turbulent Mixing ◽  
Mixing Zone

A new large cross-section shock tube for studies of turbulent mixing induced by interfacial hydrodynamic instability

Shock Waves ◽  
2003 ◽  
Vol 12 (5) ◽  
pp. 431-434 ◽  
Author(s):  
L. Houas ◽  
G. Jourdan ◽  
L. Schwaederlé ◽  
R. Carrey ◽  
F. Diaz
Keyword(s):  
Shock Tube ◽  
Cross Section ◽  
Turbulent Mixing ◽  
Hydrodynamic Instability ◽  
Large Cross Section

Turbulent Mixing Zone Development in Shock Tube Experiments with Thin Film Separation

1995 ◽  
pp. 223-226
Author(s):  
A. I. Abakumov ◽  
E. E. Meshkov ◽  
P. N. Nizovtsev ◽  
V. V. Nikiforov ◽  
V. G. Rogachov
Keyword(s):  
Thin Film ◽  
Shock Tube ◽  
Turbulent Mixing ◽  
Mixing Zone ◽  
Zone Development ◽  
Film Separation

scholarly journals Some peculiarities of turbulent mixing growth and perturbations at hydrodynamic instabilities

2013 ◽  
Vol 371 (2003) ◽  
pp. 20120291 ◽  
Author(s):  
N. V. Nevmerzhitskiy
Keyword(s):  
Shock Wave ◽  
Reynolds Number ◽  
Mach Number ◽  
Turbulent Mixing ◽  
Large Scale ◽  
Hydrodynamic Instabilities ◽  
Mixing Zone ◽  
Gaseous Media ◽  
Experimental Works ◽  
Atwood Number

The author presents a review of some experimental works devoted to the research of evolution of large-scale perturbations and turbulent mixing (TM) in liquid and gaseous media during the growth of hydrodynamic instabilities. In particular, it is shown that growth of perturbations and TM in gases is sensitive to the Mach number of shock wave; character of gas front penetration into liquid is not changed as the Reynolds number of flow increases from 5×10 5 to 10 7 ; and change of the Atwood number sign from positive to negative causes stopping of gas front penetration into liquid, but mixing zone width is expanded under inertia.

scholarly journals RFNC–VNIITF multifunctional shock tube for investigating the evolution of instabilities in nonstationary gas dynamic flows

2003 ◽  
Vol 21 (3) ◽  
pp. 381-384 ◽  
Author(s):  
Yu.A. KUCHERENKO ◽  
O.E. SHESTACHENKO ◽  
S.I. BALABIN ◽  
A.P. PYLAEV
Keyword(s):  
Shock Wave ◽  
Shock Tube ◽  
Turbulent Mixing ◽  
Wire Array ◽  
Density Ratio ◽  
Initial Pressure ◽  
Taylor Instability ◽  
Interfacial Instability ◽  
Rayleigh Taylor Instability ◽  
Dynamic Flows

The design, operation, and functionality of the multifunctional shock tube (MST) facility at the Russian Federal Nuclear Center–VNIITF are described. When complete, the versatile MST consists of three different driver sections that permit the execution of three different classes of experiments on the compressible turbulent mixing of gases induced by the (1) Richtmyer–Meshkov instability (generated by a stationary shock wave with shock Mach numbers <5), (2) Rayleigh–Taylor instability (generated by compression wave such that acceleration of the interface is <105g0, whereg0= 9.8 m/s2), and (3) combined Richtmyer–Meshkov and Rayleigh–Taylor instability (generated by a nonstationary shock wave with initial pressure at the front 5 × 106Pa and acceleration of ≤106g0of the interface). For each of these types of experiments, the density ratio of the gases is ρ2/ρ1≤ 34. Perturbations are imposed on a thin membrane, embedded in a thin wire array of microconductors that is destroyed by an electric current. In addition, various limitations of experimental techniques used in the study of interfacial instability generated turbulent mixing are also briefly discussed.

Sign in / Sign up

Export Citation Format

Share Document