Accession Number : AD0278487

Title :   ON THE PROPAGATION OF AERODYNAMIC DISTURBANCES FAR FROM A BODY RISING THROUGH THE ATMOSPHERE

Corporate Author : RAND CORP SANTA MONICA CALIF

Personal Author(s) : MEYER,RICHARD E.

Report Date : JUN 1962

Pagination or Media Count : 1

Abstract : The far field of a body rising vertically at supersonic speed is studied through the acoustic approximation to obtain an insight into the effect which the atmospheric density stratification has on the propagation of the shocks and pressure waves generated by the body. Apart from the density stratification per se, the gravitational acceleration is found to have a major influence when the waves are followed over heights of several miles or more. The absolute pressure and density perturbations due to the body decrease with height while the velocity and particle displacement increase. The decay of the perturbation behind the shock is oscillatory, in contrast to its monotonic character in a uniform medium. At any point at considerable height and distance from the flight path, the air will experience a sudden, surprisingly large, upward nd outward displacement, followed by a reversal and oscillatory decay in time. The natural decay of the perturbation with distance from the body is counteracted by certain effects. The acoustic results obtained usually give a reliable picture of the wave propagation up to heights of the order of 50 km. (Author)

Descriptors :   AERODYNAMIC CHARACTERISTICS, DENSITY, GRAVITY, PARTIAL DIFFERENTIAL EQUATIONS, PERTURBATION THEORY, PRESSURE, SOUND TRANSMISSION

Distribution Statement : APPROVED FOR PUBLIC RELEASE