PASSAGE THROUGH RESONANCE OF ROLLING FINNED PROJECTILES WITH CENTER-OF-MASS OFFSET
✍ Scribed by A. SHARMA; N. ANANTHKRISHNAN
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- English
- Weight
- 236 KB
- Volume
- 239
- Category
- Article
- ISSN
- 0022-460X
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✦ Synopsis
Finned projectiles that are meant to be unspun could acquire small roll rates in #ight due to slight con"gurational asymmetries. If the roll rate matches the natural yawing frequency of the projectile, a resonance phenomenon takes place resulting in yaw ampli"cation, and possible loss of stability. To avoid this, "nned projectiles are deliberately spun to a roll rate well beyond the resonance value. This gives rise to a passage-through-resonance phenomenon in the #ight of "nned projectiles. Finned projectiles passing through resonance are known to exhibit the phenomena of roll lock-in, transient resonance, and catastrophic yaw. Projectiles locked in at the resonance condition experience large yaw and are likely to lose the desired #ight path. On the other hand, transient resonance is a milder phenomenon where the projectile locks in at resonance brie#y before continuing to build-up to the design value. However, the yaw ampli"cation during the brief period of resonance may be su$cient to destabilize the projectile. The problem of passage through resonance of "nned projectiles with a center-of-mass o!set is considered in this paper. Roll lock-in and transient resonance at normal and reverse resonance is shown. It is observed that the yaw ampli"cation at transient resonance is much lower than that at lock-in. The lack of yaw ampli"cation can be understood based on the bifurcation analysis and numerical simulations reported in this paper.