Progress in Plasma Processing of Materials, 1999

ISBN Print: 1-56700-126-2

ABOUT THE STRUCTURE OF RADIATING POWERFUL SHOCK WAVES

DOI: 10.1615/ITPPC-1998.110
pages 67-75

Abstrakt

Meteoric bodies travel through the Earth's atmosphere at velocities V~10−70 km/s. In the upper layers of the atmosphere interaction with the environment takes place in the free molecular stream mode. At lower altitudes transition to the gas-dynamics mode with formation of a powerful shock wave (SW) is observed (according to [1], the transition altitude is 120−100 km for bodies the diameter of which is d >10 m). The air behind the shock wave front is heated up to temperatures T~104−105 K, considerably ionized and becomes a source of intensive radiation with a characteristic flux density S~109 W/cm2.
Problems related to the structure of powerful radiating shock waves created at penetration of the Earth's atmosphere by large meteorites are considered in this paper. Data on shock adiabatic curves of air obtained both in the supposition of complete thermodynamic equilibrium of air behind the shock wave front, and with account of possible transparency of gas for self radiation are presented. The hierarchy of scales of various physical processes in a shock wave permitting to simplify solution of the problem concerning the front structure is considered. The modes of SW propagation, profiles of parameters, spatial scales, spectral and integrated radiation fluxes have been determined for various heights and velocities.