Calculation of elastic tanks partially filled with liquid, for prediction of the POGO effect
Abstract
The POGO vibrational instability effect is due to a coupling between the principal structure of a launcher, the so-called secondary structure, and the thrust. Thrust fluctuations generate longitudinal vibrations which in turn bring about pressure vibrations, leading again to thrust variations. To predict the POGO effect it is necessary to calculate as exactly as possible the vibratory behavior of elastic tanks partially filled with liquids. A general method was developed which makes the calculation possible in the case of perfect incompressible liquids. The method is one of finite elements which combines structural and fluid elements. It was verified for a number of significant cases, and extended theoretically to the case of perfect compressible liquids contained in elastic tanks or pipes and in irrotational flow.
- Publication:
-
La Recherche Aerospatiale
- Pub Date:
- September 1975
- Bibcode:
- 1975ReAeB.......70V
- Keywords:
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- Elastic Properties;
- Liquid Filled Shells;
- Performance Prediction;
- Pogo Effects;
- Propellant Tanks;
- Structural Vibration;
- Boundary Value Problems;
- Finite Element Method;
- Incompressible Fluids;
- Linearization;
- Matrices (Mathematics);
- Fluid Mechanics and Heat Transfer