The Anomalous Refraction of ShockWaves in Materials with General Equations of State. Part II Anomalous Refraction Wave Systems

Journal Article · Wed Apr 01 04:00:00 EDT 2009 · Proceedings of the Royal Society A

OSTI ID:924129

Puckett, Elbridge Gerry ^[1]; Henderson, L F

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1. University of California, Davis

In Part II we develop a theory of anomalous refraction with which one can predict the structure of the shock wave at the material interface as a function of the strength of the incident shock wave, the angle that the incident shock makes with the material interface, and the material properties of the two materials.We show that the critical angle for the onset of anomalous refraction is satisfied in at least three circumstances. Firstly, the classical case when the system is fast-slow a > 1 and the incident shock is over-run by downstream expansion waves and the wave impedance Z decreases. Secondly, even with increasing Z, and still with a > 1, the critical angle can be attained with a reflected compression. Thirdly, for a slow-fast system a < 1, the critical angle can be obtained with precursor waves which may be either shocks or evanescent compressions. We present conditions for the onset of evanescence. We find that the classical model of anomalous refraction is only partly correct, a remnant of a centered expansion wave must be added to it and its existence is confined to refractions that we define as being weak. A variety of degenerate anomalous refractions are discussed. They are essentially the regular and irregular shock pair refractions described in Part I. In the regime for which experiments have been conducted (i.e., for relatively weak shocks) we demonstrate that our theory agrees completely with available experimental data (e.g., Jahn 1956, Abdel- Fattah & Henderson 1978a) and with our computations. However, our theory also predicts a shock structure that has not yet been observed experimentally in the Air/CO2 gas combination, since this structure occurs when the incident shock is relatively strong; i.e., with a shock Mach number of 10 or greater. We have verified these predictions with our computations and expect that they will eventually be confirmed by experiment.

• Research Organization: The Regents of the University of California
• Sponsoring Organization: USDOE - Office of Science (SC)
• DOE Contract Number: FC02-01ER25473
• OSTI ID: 924129
• Report Number(s): DOE-UCDAVIS-25473-02
• Journal Information: Proceedings of the Royal Society A, Journal Name: Proceedings of the Royal Society A
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Anomalous Shock Refraction
Shock Refraction