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Centaur engine gimbal friction characteristics under simulated thrust load
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Askew, J. W. |
| Copyright Year | 1986 |
| Description | An investigation was performed to determine the friction characteristics of the engine gimbal system of the Centaur upper stage rocket. Because the Centaur requires low-gain autopilots in order to meet all stability requirements for some configurations, control performance (response to transients and limit-cycle amplitudes) depends highly on these friction characteristics. Forces required to rotate the Centaur engine gimbal system were measured under a simulated thrust load of 66,723 N (15,000 lb) and in an altitude/thermal environment. A series of tests was performed at three test conditions; ambient temperature and pressure, ambient temperature and vacuum, and cryogenic temperature and vacuum. Gimbal rotation was controlled, and tests were performed in which rotation amplitude and frequency were varied by using triangular and sinusoidal waveforms. Test data revealed an elastic characteristic of the gimbal, independent of the input signal, which was evident prior to true gimbal sliding. The torque required to initiate gimbal sliding was found to decrease when both pressure and temperature decreased. Results from the low amplitude and low frequency data are currently being used in mathematically modeling the gimbal friction characteristics for Centaur autopilot performance studies. |
| File Size | 640187 |
| Page Count | 24 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19860022149 |
| Archival Resource Key | ark:/13960/t8md3t78s |
| Language | English |
| Publisher Date | 1986-09-01 |
| Access Restriction | Open |
| Subject Keyword | Launch Vehicles And Space Vehicles Low Temperature Tests Centaur Launch Vehicle Gimbals Altitude Simulation Servocontrol Automatic Pilots Environmental Tests Friction Factor Rotation Thrust Loads Kinetic Friction Thrust Vector Control Upper Stage Rocket Engines Mathematical Models Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
