Flowfield measurements in the vortex wake of a missile at high angle of attack in turbulence
Howard, Richard M.
MetadataShow full item record
The flowfield downstream of a vertically-launched surface-to-air missile model at an angle of attack of 50° and a Reynolds number of 1.1 x 10(5) was investigated in a wind tunnel of the Naval Postgraduate School. The goal of this thesis is to experimentally validate the pressure measurement system for flowfield variables with elevated levels of turbulence; to determine the location and intensity of the asymmetric vortices in the wake of the VLSAM model at a raised level of freestream turbulence; and to display the asymmetric vortices by velocity mapping and pressure contours. The purpose is to correlate the results with the force measurements of Rabang to provide a greater understanding of the vortex flowfield. The body-only configuration was tested. Two flowfield conditions were treated: the nominal ambient wind tunnel condition, and a condition with grid generated turbulence of 3.8% turbulence intensity and a dissipation length scale of 1.7 inches. The following conclusions were reached: 1) The relative strengths of the asymmetric vortices can be noted by the sharp spike shape in the ambient condition; this condition becomes diffused and becomes fatter in the turbulent condition; 2) The right side vortex has greater strength than the left side one as seen by the diffusion in the total pressure coefficient and static pressure coefficient contours with and without a turbulent condition; 3) an increase in turbulence intensity tends to reduce the strength of the asymmetric nose-generated vortices; also pushes the two asymmetric vortices closer together; 4) and crossflow velocities were examined and were found to indicate the behavior denoted by the pressure contours.
RightsCopyright is reserved by the copyright owner
Showing items related by title, author, creator and subject.
Johnson, Dan A. (Monterey, California. Naval Postgraduate School, 1989);The flowfield about a vertically-launched surface-to-air missile model at an angle of attack of 50 degrees and a Reynolds number of 1.1x10(5) was investigated in a low-speed wind tunnel at the Naval Postgraduate School. ...
Yuan, Chih-Chung (Monterey, California. Naval Postgraduate School, 1990);Wind tunnel tests were conducted on a vertically launched surface-to- air missile model to investigate the effects of forebody stakes on the side forces and yawing moments induced by nose-generated asymmetric vortices at ...
O'Leary, John F. (Monterey, California. Naval Postgraduate School, 1992);A nulling five-hole pressure probe was used to complete a flowfield survey behind a close-coupled canard and wing model set a 32 degrees angle of attack. The canard and wing were both low-aspect-ratio, highly swept, delta ...