Ground Plane Effects on a Contoured Surface at Low Subsonic Velocities.
Abstract
The wing-in-ground effect phenomenon was examined by investigating the flow between a flat ground plate and a contoured upper plate. Velocity and turbulence intensity measurements were taken at various points in the flow with a Laser Doppler Velocimeter. Mach numbers studied were Mach 0.15 and Mach 0.2 at the exit plane of a 1 cm by 10 cm two-dimensional nozzle. Measurements were taken across the width of the jet, 5, 10, and 15 cm downstream with plate separations of 1, 2, and 5 cm and vertically without the ground plate. In addition measurements were taken near the top plate with conventional pressure measuring techniques and the results compared. The proximity of the ground plate had the effect of spreading the flow outward across the 10 cm width of the jet by 20%. The laser velocimeter showed the turbulence intensity to be constant across the potential core of the jet. Turbulence intensity increased beyond 10% in the boundary layers of the jet and in the plate boundary layer. The pressure measurement data correlated well with the laser velocimeter results.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1979
- Accession Number
- ADA079877
Entities
People
- Joseph A. Krawtz
Organizations
- Air Force Institute of Technology