scholarly journals Planar shock cylindrical focusing by a perfect-gas lens

2006 ◽  
Vol 18 (3) ◽  
pp. 031705 ◽  
Author(s):  
P. E. Dimotakis ◽  
R. Samtaney
Keyword(s):  
Perfect Gas ◽  
Planar Shock

Planar Shock Focusing Through Perfect Gas Lens: First Experimental Demonstration

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Laurent Biamino ◽  
Christian Mariani ◽  
Georges Jourdan ◽  
Lazhar Houas ◽  
Marc Vandenboomgaerde ◽  
...  
Keyword(s):  
Shock Wave ◽  
Shock Tube ◽  
Incident Shock ◽  
Incident Shock Wave ◽  
Shock Acceleration ◽  
Perfect Gas ◽  
Shock Focusing ◽  
Planar Case ◽  
Planar Shock ◽  
Planar Shock Wave

When a shock wave crosses an interface between two materials, this interface becomes unstable and the Richtmyer–Meshkov instability develops. Such instability has been extensively studied in the planar case, and numerous results were presented during the previous workshops. But the Richtmyer–Meshkov (Richtmyer, 1960, “Taylor Instability in Shock Acceleration of Compressible Fluids,” Commun. Pure Appl. Math., 13(2), pp. 297–319; Meshkov, 1969, “Interface of Two Gases Accelerated by a Shock Wave,” Fluid Dyn., 4(5), pp. 101–104) instability also occurs in a spherical case where the convergence effects must be taken into account. As far as we know, no conventional (straight section) shock tube facility has been used to experimentally study the Richtmyer–Meshkov instability in spherical geometry. The idea originally proposed by Dimotakis and Samtaney (2006, “Planar Shock Cylindrical Focusing by a Perfect-Gas Lens,” Phys. Fluid., 18(3), pp. 031705–031708) and later generalized by Vandenboomgaerde and Aymard (2011, “Analytical Theory for Planar Shock Focusing Through Perfect Gas Lens and Shock Tube Experiment Designs,” Phys. Fluid., 23(1), pp. 016101–016113) was to retain the flexibility of a conventional shock tube to convert a planar shock wave into a cylindrical one through a perfect gas lens. This can be done when a planar shock wave passes through a shaped interface between two gases. By coupling the shape with the impedance mismatch at the interface, it is possible to generate a circular transmitted shock wave. In order to experimentally check the feasibility of this approach, we have implemented the gas lens technique on a conventional shock tube with the help of a convergent test section, an elliptic stereolithographed grid, and a nitrocellulose membrane. First experimental sequences of schlieren images have been obtained for an incident shock wave Mach number equal to 1.15 and an air/SF6-shaped interface. Experimental results indicate that the shock that moves in the converging part has a circular shape. Moreover, pressure histories that were recorded during the experiments show pressure increase behind the accelerating converging shock wave.

EQUILIBRIUM AND PERFECT GAS AIR BEHAVIOR IN THE STAGNATION REGION

2018 ◽  
Author(s):  
Paulo Toro ◽  
Guilherme Icaro Andrade de Oliveira ◽  
Lucas Carvalho ◽  
Luísa Mirelle Santos ◽  
Raul Farias ◽  
...  
Keyword(s):  
Perfect Gas ◽  
Stagnation Region

scholarly journals Study on Mach stems induced by interaction of planar shock waves on two intersecting wedges

2015 ◽  
Vol 32 (3) ◽  
pp. 362-368 ◽  
Author(s):  
Gaoxiang Xiang ◽  
Chun Wang ◽  
Honghui Teng ◽  
Yang Yang ◽  
Zonglin Jiang
Keyword(s):  
Shock Waves ◽  
Planar Shock

Impacts of grid turbulence on the side projection of planar shock waves

Shock Waves ◽  
2021 ◽  
Author(s):  
G. Fukushima ◽  
S. Ogawa ◽  
J. Wei ◽  
Y. Nakamura ◽  
A. Sasoh
Keyword(s):  
Shock Waves ◽  
Grid Turbulence ◽  
Planar Shock

scholarly journals Some nozzle flows found by the hodograph method

1959 ◽  
Vol 1 (1) ◽  
pp. 80-94 ◽  
Author(s):  
T. M. Cherry
Keyword(s):  
Exact Solutions ◽  
Two Dimensions ◽  
Nozzle Design ◽  
Perfect Gas ◽  
Field Equations ◽  
Rigid Boundary ◽  
Hodograph Method ◽  
Isentropic Flow ◽  
Fixed Boundaries ◽  
Nozzle Flows

For investigating the steady irrotational isentropic flow of a perfect gas in two dimensions, the hodograph method is to determine in the first instance the position coordinates x, y and the stream function ψ as functions of velocity compoments, conveniently taken as q (the speed) and θ (direction angle). Inversion then gives ψ, q, θ as functions of x, y. The method has the great advantage that its field equations are linear, so that it is practicable to obtain exact solutions, and from any two solutions an infinity of others are obtainable by superposition. For problems of flow past fixed boundaries the linearity of the field equations is usually offset by non-linearity in the boundary conditions, but this objection does not arise in problems of transsonic nozzle design, where the rigid boundary is the end-point of the investigation.

One-dimensional adiabatic flow of equilibrium gas–particle mixtures in long vertical ducts with friction

1989 ◽  
Vol 203 ◽  
pp. 251-272 ◽  
Author(s):  
Guido Buresti ◽  
Claudio Casarosa
Keyword(s):  
Equilibrium Mixture ◽  
Adiabatic Heating ◽  
Explosive Eruptions ◽  
Perfect Gas ◽  
Typical Application ◽  
One Dimensional ◽  
Adiabatic Flow ◽  
Flow Parameters ◽  
Constant Area ◽  
Inlet Conditions

The equations of the steady, adiabatic, one-dimensional flow of an equilibrium mixture of a perfect gas and incompressible particles, in constant-area ducts with friction, are derived taking into account the effects of gravity and of the finite volume of the particles. As is the case for a pure gas, the mixture is shown to be subject to the phenomenon of choking, and the possibility of an adiabatic heating of the mixture in a subsonic expansion is also theoretically predicted for certain flow inlet conditions. The model may be used to approximately describe the conditions existing in portions of volcanic conduits during the Plinian phases of explosive eruptions. Some results of the numerical integration of the equations for a typical application of this type are briefly discussed, thus showing the potential of the model for carrying out rapid analyses of the influence of the main geometrical and flow parameters describing the problem. A non-volcanological application is also analysed to illustrate the possibility of the adiabatic heating of the mixture.

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