Accession Number:

AD0860122

Title:

Optimal Control of Ablation during Hyperbolic Entry.

Personal Author(s):

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

Report Date:

1969-06-01

Abstract:

Methods of controlling the ablation rate of a spherical body entering the earths atmosphere at hyperbolic velocities are investigated. Expulsion of air to force the shock wave away from the body and increase drag is shown to be impractical as a means of control for minimizing the ablation rate. Optimization by the gradient method with density of the ablation material as the control results in the maximum terminal diameter of the vehicle being achieved by selection of the ablative material with the highest density, other parameters being equal. However, density is shown to be a relatively ineffective control when compared with the materials heat of ablation. Empirical equations for calculating the heat transfer due to convective and radiative processes are used. Approximate equations are developed to express the relationships between heating rates, ablation rates, shock standoff distance, and drag, providing a means of relating material qualities to the equations of motion of a spherical entry body. Author

Descriptive Note:

Master's thesis,

Pages:

0110

Subject Categories:

File Size:

0.00MB

Full text not available:

Request assistance