Accession Number : AD0257938

Title :   THEORY OF IONIZED TRAILS FOR BODIES AT HYPERSONIC SPEEDS

Corporate Author : RAND CORP SANTA MONICA CALIF

Personal Author(s) : LYKOUDIS,P.S.

Report Date : 29 MAY 1961

Pagination or Media Count : 1

Abstract : The characteristics of the gaseous trail remaining behind a body moving through the atmosphere at hypersonic speeds are discussed. Means are sought for ascertaining those variables that can be measured and used to predict the characteristics of the body causing the trail, essentially its shape and weight. In the case of thermodynamic equilibrium, a universal solution is found for the velocity and enthalpy distributions at a station behind the body where the pressure has reached its ambient free-stream value. This solution is given in terms of the coordinate defining the shape of the bow shock wave. The nondimensional velocity and enthalpy profiles depend strongly on the drag coefficient alone. The Thermal-conduction part of the trail is also studied. An analytic solution is found for the case of variable thermal conductivity. The length of the trail based on a minimum ionization level is calculated at different altitudes for an illustrative re-entry. Within a good approximation this length is directly proportional to the local atmospheric density, to the drag coefficient, and to the objects's cross-sectional area, for a constant flight velocity and for a relatively blunt body with boundary-layer effects neglected. The influence of the trailing shock on the conduction part of the trail is discussed. A preliminary study is also made of the trail under chemically frozen conditions. (Author)

Descriptors :   *ATMOSPHERE ENTRY, *GAS IONIZATION, *REENTRY VEHICLES, AERODYNAMIC CHARACTERISTICS, AERODYNAMIC CONFIGURATIONS, ATMOSPHERES, FLUID MECHANICS, GASES, GUIDED MISSILES, HYPERSONIC CHARACTERISTICS, THERMODYNAMICS, WAKE

Distribution Statement : APPROVED FOR PUBLIC RELEASE