Some Dynamic Effects of Fuel Motion in Simplified Model Tip Tanks on Suddenly Excited Bending Oscillations
Abstract
An exploratory investigation of the dynamic effects of fuel sloshing in tip tanks on suddenly excited bending oscillations was conducted with two simplified model beam-tank systems. The larger system consisted of a cylindrical tank 7.5 inches in diameter and 10 inches long mounted on the tip of an 80-inch cantilever beam and the smaller system consisted of a cylindrical tank 4.2 inches in diameter and 6.9 inches long mounted on the tip of an 18-inch cantilever beam. Several fluids of different densities and viscosities (water, carbon tetrachloride, benzene, and linseed oil) were used in combination with various conditions of tank fullness. Recorded oscillations of the beams after sudden release from an initially deflected position showed the effects both of fluid damping and of the variation in effective mass on the beam motion. High-speed motion pictures were used to study the fluid motion. a Envelope curves of the beam-displacement time histories are compared to show the effects on the oscillations of variation in tank fullness, fluid density, fluid viscosity, and tank shape. The effective weight of fluid for the smaller test system is shown for each successive cycle of vibration, and the variation of effective fluid weight with tank fullness is presented. The results of this investigation indicate that after several cycles substantial damping may be obtained from fuel sloshing in a tip tank and the effective mass of the fuel may vary considerably under certain conditions of tank oscillation. For the fluids tested no effects attributable to viscosity were observed but for a given beam-tank system the density of fluid and tank fullness were found to be important parameters.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1952
- Accession Number
- ADA377099
Entities
People
- Bertrand H. Stephenson
- Kenneth F. Merten
Organizations
- National Aeronautics and Space Administration