Accession Number:

ADA214730

Title:

Investigation of Liquid Sloshing in Spin-Stabilized Satellites

Descriptive Note:

Final rept. 1 Jan 1986-31 Aug 1989

Corporate Author:

IOWA STATE UNIV AMES DEPT OF MECHANICAL ENGINEERING

Report Date:

1989-08-31

Pagination or Media Count:

290.0

Abstract:

Launching of several Star 48 communications satellites from the space shuttle has consistently resulted in a nutating of the spacecraft. Sloshing fluid stores were suspected as the source of this dynamic instability. A mathematical model of the sloshing fluid motion coupled with the satellite dynamics was developed and the launch phase simulated. The flight simulation shows similar behavior when compared to the telementered flight data. Additionally, a control law was developed using an equivalent mechanical model of the fluid motion which results in a stable dynamic system. The control law may also be used for pointing maneuvers and is implemented by sensing only the main body angular rates and attitude. An experimental satellite-simulator test rig was designed and built to study the interaction of the sloshing fluid and spinning structure. The test rig was instrumented to monitor the motion of several rotating configurations. A mathematical model of the simulator was developed and is presented. Simulation of experimental results has been achieved. The computational fluid dynamic analysis has now developed a primitive variables numerical algorithm for a two-dimensional and three-dimensional sloshing problem. The key feature of the formulation is use of a coordinate transformation that maps the fluid body into the fixed geometric shape of the containing rectangle or sphere. The formulation removes an initial singularity from the governing equations that would otherwise cause the numerical method to diverge. Satellite coning.

Subject Categories:

  • Fluid Mechanics
  • Spacecraft Trajectories and Reentry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE