Accelerating Shock Waves in a Laser‐produced Density Gradient

2000 ◽  
Vol 127 (2) ◽  
pp. 503-508 ◽  
Author(s):  
Romain Teyssier ◽  
Dmitri Ryutov ◽  
Bruce Remington
Keyword(s):  
Shock Waves ◽  
Density Gradient

Density gradient measurements of F2 dissociation rates in shock waves

1973 ◽  
Vol 58 (11) ◽  
pp. 5176-5177 ◽  
Author(s):  
W. Dale Breshears ◽  
Paul F. Bird
Keyword(s):  
Shock Waves ◽  
Density Gradient ◽  
Gradient Measurements

Density Gradient Measurements of O2 Dissociation in Shock Waves

1971 ◽  
Vol 55 (8) ◽  
pp. 4017-4026 ◽  
Author(s):  
W. D. Breshears ◽  
P. F. Bird ◽  
John H. Kiefer
Keyword(s):  
Shock Waves ◽  
Density Gradient ◽  
Gradient Measurements ◽  
O2 Dissociation

Density gradient measurements of Cl2 dissociation in shock waves

1977 ◽  
Vol 67 (3) ◽  
pp. 881 ◽  
Author(s):  
Robert J. Santoro ◽  
Gerald J. Diebold ◽  
George J. Goldsmith
Keyword(s):  
Shock Waves ◽  
Density Gradient ◽  
Gradient Measurements

Dust-acoustic shock waves: Effect of plasma density gradient

2005 ◽  
Vol 12 (5) ◽  
pp. 052314 ◽  
Author(s):  
De-long Xiao ◽  
J. X. Ma ◽  
Yang-fang Li
Keyword(s):  
Shock Waves ◽  
Density Gradient ◽  
Plasma Density ◽  
Dust Acoustic

The Sensitivity and Range Required in a Toepler Schlieren Apparatus for Photography of High-Speed Air Flow

1954 ◽  
Vol 4 (1) ◽  
pp. 19-50
Author(s):  
W. A. Mair
Keyword(s):  
Theoretical Analysis ◽  
Shock Waves ◽  
Density Gradient ◽  
Boundary Layers ◽  
High Speed ◽  
Opposite Sign ◽  
Geometrical Optics ◽  
Air Stream ◽  
Light Rays ◽  
Curved Shock Waves

SummaryA simple theoretical analysis is given of the quantities affecting the sensitivity and range of a schlieren apparatus. In regions of large density gradient the deflections of the light rays may lie outside the normal working range. When this occurs, dark regions may appear in parts of the photograph that would normally be light. Examples of this effect are given, and it is shown that confusion can be avoided by taking photographs in pairs, with the knife edges or slits arranged to give sensitivities of opposite sign.The deflections of light rays in various typical disturbances in a supersonic air stream are calculated, using geometrical optics. Prandtl-Meyer expansions, boundary layers, and plane and curved shock waves are considered. From these calculated deflections it is shown that some of the anomalous effects commonly observed in schlieren photographs can be explained.

Density Gradient Measurements of HCl Dissociation in Shock Waves

1972 ◽  
Vol 56 (11) ◽  
pp. 5347-5351 ◽  
Author(s):  
W. D. Breshears ◽  
P. F. Bird
Keyword(s):  
Shock Waves ◽  
Density Gradient ◽  
Gradient Measurements

Activated Prominences; Mechanisms for Activation and Eruption

1979 ◽  
Vol 44 ◽  
pp. 307-313
Author(s):  
D.S. Spicer
Keyword(s):  
Pressure Gradient ◽  
Density Gradient ◽  
Current Density ◽  
Convective Instability ◽  
Tearing Mode ◽  
Magnetic Shear ◽  
Long Wavelength ◽  
Ideal Mhd ◽  
Gradient Change ◽  
Accelerated Particles

A possible relationship between the hot prominence transition sheath, increased internal turbulent and/or helical motion prior to prominence eruption and the prominence eruption (“disparition brusque”) is discussed. The associated darkening of the filament or brightening of the prominence is interpreted as a change in the prominence’s internal pressure gradient which, if of the correct sign, can lead to short wavelength turbulent convection within the prominence. Associated with such a pressure gradient change may be the alteration of the current density gradient within the prominence. Such a change in the current density gradient may also be due to the relative motion of the neighbouring plages thereby increasing the magnetic shear within the prominence, i.e., steepening the current density gradient. Depending on the magnitude of the current density gradient, i.e., magnetic shear, disruption of the prominence can occur by either a long wavelength ideal MHD helical (“kink”) convective instability and/or a long wavelength resistive helical (“kink”) convective instability (tearing mode). The long wavelength ideal MHD helical instability will lead to helical rotation and thus unwinding due to diamagnetic effects and plasma ejections due to convection. The long wavelength resistive helical instability will lead to both unwinding and plasma ejections, but also to accelerated plasma flow, long wavelength magnetic field filamentation, accelerated particles and long wavelength heating internal to the prominence.

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