Space Shuttle Response to Acoustic Combustion Instability in the solid Rocket Boosters.
Abstract
Response of the Space Shuttle vehicle to unstable acoustic pressure oscillations in the solid rocket boosters (SRB's) was calculated. The response was expressed in terms of forces and displacements at the attach points between the SRB's and the External Tank (ET), and between the ET and the Orbiter. The response calculations satisfied the objectives of the program. The NASTRAN computer program was used to analyze the various finite element shuttle models. Finite element models of the SRB, ET, and Orbiter were supplied by North American Rockwell. A detailed finite element model of the solid rocket motor (SRM) was constructed for use with the cyclic symmetry option in NASTRAN. The models were analyzed separately and results were combined to represent the total structure by using a mechanical impedance-type approach. Some hand calculations were performed to estimate the axial connection point force and displacement. The good agreement between hand calculation and computer solution provided some confidence in the computer solution. A maximum attach point load of 1600 lbs was calculated for a + or - 1.0 psi pressure oscillation level. Therefore, maximum attach point loads of 16,000 to 32,000 lbs can be expected for maximum pressure oscillation levels of + or - 10 to + or - 20 psi. The attach point loads would be applied at a frequency of 15.25 Hz.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1976
- Accession Number
- ADA037157
Entities
People
- F. R. Jensen