Title

Flight Simulation of Orbital and Reentry Vehicles Part II - A Modified Flight Path Axis System for Solving the Six-Degree-of-Freedom Flight Equations

Description

Three translational and three rotational equilibrium equations for an orbital vehicle subject to aerodynamic and jet reaction forces are derived using a modified flight-path axis system for the translational equations. The dependent variables of the system are horizontal velocity component, vertical velocity component, and flight-path heading angle. The resulting equations are shown to have advantages for computer mechanization over alternative axis systems for the translational equations. Complete equations for determining vehicle orientation, instantaneous latitude and longitude, angle of attack, angle of sideslip, aerodynamic forces and moments, etc., are presented. Modifications in the translational equations which allow direct solution by an analog computer are also given. Analog computer mechanization of these equations in both real and fast time is described, including a novel technique for division which preserves favorable multiplier scaling. Specific machine results are presented which demonstrate accurate solution of close-satellite trajectories, including re-entry from satellite altitudes to sea level. With no change in circuit or scaling the same computer mechanization yields zero-drag orbits which close within several hundred feet of altitude.

Date

1961

Index Abstract

Contrails and DTIC truncated

Photo Quality

Not Needed

Report Number

ASD TR 61-171 (II)

Creator

Fogarty, L. E.

Howe, R. H.

Corporate Author

University of Michigan

Laboratory

Behavioral Sciences Laboratory

Extent

41

Identifier

AD0269283

AD0269283

Access Rights

OTS

Distribution Classification

1

Contract

AF 33(616)-5644

DoD Project

8(7-114)

DoD Task

611407

DTIC Record Exists

No

Distribution Change Authority Correspondence

None

Abstract

Three translational and three rotational equilibrium equations for an orbital vehicle subject to aerodynamic and jet reaction forces are derived using a modified flight-path axis system for the translational equations. The dependent variables of the system are horizontal velocity component, vertical velocity component, and flight-path heading angle. The resulting equations are shown to have advantages for computer mechanization over alternative axis systems for the translational equations. Complete equations for determining vehicle orientation, instantaneous latitude and longitude, angle of attack, angle of sideslip, aerodynamic forces and moments, etc., are presented. Modifications in the translational equations which allow direct solution by an analog computer are also given. Analog computer mechanization of these equations in both real and fast time is described, including a novel technique for division which preserves favorable multiplier scaling. Specific machine results are presented which demonstrate accurate solution of close-satellite trajectories, including re-entry from satellite altitudes to sea level. With no change in circuit or scaling the same computer mechanization yields zero-drag orbits which close within several hundred feet of altitude.

Report Availability

Full text available

Date Issued

1961-10

Provenance

RAF Centre of Aviation Medicine

Type

report

Format

1 online resource ( x, 31 pages) : ill.

Subject

Flight Simulators

Reentry Vehicles

Artificial Satellites

Analog Computers

Atmosphere Entry

Differential Equations

Dynamics

Equations

Flight Paths

Mathematical Analysis

Orbits

Pilots

Training Devices

Vector Analysis

Publisher

Wright-Patterson Air Force Base, OH : Behavioral Sciences Laboratory, Aerospace Medical Laboratory, Aeronautical Systems Division, Air Force Systems Command, United States Air Force

Distribution Conflict

No