Moment Induced by Liquid Payload during Spin-Up Without a Critical Layer.
Abstract
For a fully spun-up liquid payload, eigenfrequencies and liquid side moments induced by projectile coning motion have been computed by a linear boundary layer theory. For partially spun-up liquids, this theory can fail due to the presence of a critical layer in which the local angular velocity of the spinning motion is near the angular velocity of the projectile's coning motion. Late in the spin-up process, when more than 90% of the spin angular momentum has been acquired by the liquid, a critical layer usually does not exist. In this report, a linear-boundary-layer theory is developed to predict eigenfrequencies and the liquid moment during late spin-up times. The predicted eigenfrequencies agree well with those computed by the linearized Navier-Stokes technique of Gerber and Sedney. The side moments predicted by the linear-boundary-layer theory are available to projectile designers for flight stability analysis.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1984
- Accession Number
- ADA145716
Entities
People
- C. H. Murphy
Organizations
- Ballistic Research Laboratory