Flowfield Effects of Launch on a Vertically-Launched Missile
Abstract
The flowfield about a vertically-launched surface-to-air missile model at an angle of attack of 50 deg and a Reynolds number of 110,000 was investigated in a low speed wind tunnel at the NPG School. The goal of this thesis is to determine the location and intensity of the asymmetric vortices in the wake of the VLSAM model and to display these vortices by velocity mapping and pressure contours. The two model configurations tested were for a cruciform missile with wings and tails; one at 0 deg roll angle ('plus' aspect) and the other at a 45 deg roll angle ('cross' aspect). Two flowfield conditions were treated: the nominal ambient wind tunnel condition and a condition with a grid- generated turbulence of length scale 1.08 inches and 1.88% turbulence intensity. The turbulence length scale is 61.7% of model diameter and 4.7% of model length. Conclusions include: 1) an increase in turbulence intensity tended to reduce the strength of the asymmetric nose generated vortices; 2) the two asymmetric vortices remained in approximately the same position for an increase in turbulence; 3) cross aspect vortices were more diffused, slightly larger and centered further away from the model surface than those of the plus aspect body configuration, which correlates with the differences in induced side forces for these configurations observed by Rabang; 4) the top vortex of the two asymmetric vortices was closer to the model surface and appeared to be stronger for both configurations; and 5) addition of wings and tails did not greatly alter the vortex pattern around the missile model nose. Surface-to-air missile; High- angle-of-attack aerodynamics; Turbulence; Body of revolution; Vortex asymmetry.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1989
- Accession Number
- ADA214468
Entities
People
- John J. Viniotis
Organizations
- Naval Postgraduate School