Accession Number:

ADA093741

Title:

Roll Resonance Control of Angle of Attack for Reentry Vehicle Drag Modulation

Descriptive Note:

Interim rept.

Corporate Author:

AEROSPACE CORP EL SEGUNDO CA AEROPHYSICS LAB

Personal Author(s):

• Platus, D. H.

Report Date:

1980-12-10

Pagination or Media Count:

29.0

Abstract:

Slender ballistic reentry vehicles are highly susceptible to roll rate changes caused by small asymmetries in mass and configuration. One particular combination of asymmetries, consisting of a body-fixed trim angle of attack and a small radial c.g. offset, can cause a rapid spinup into resonance, with a large amplification in trim angle of attack and a concomitant increase in drag. By controlling the magnitude and direction of the c.g. offset with a moving-mass roll control system, it is possible to control the roll rate near resonance and to limit the angle-of-attack and drag response to a controlled value. A feedback law is derived, and the control system is demonstrated with a digital-computer simulation of the equations of rotational motion. Author

Descriptors:

• *REENTRY VEHICLES
• *ROLL
• *ASYMMETRY
• *RESONANCE
• COMPUTERIZED SIMULATION
• ATTITUDE CONTROL SYSTEMS
• SLENDER BODIES
• ATMOSPHERE ENTRY
• ANGLE OF ATTACK
• CONTROL THEORY
• DRAG
• AERODYNAMICS
• TRIM ANGLE

Subject Categories:

• Guided Missile Reentry Vehicles
• Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE