Experimental Study of Wing-in-Ground Effects in the AFIT 5-Foot Wind Tunnel
Abstract
The effect of flying close to the earth's surface on the lift to drag ratio (L/D) was investigated. This was accomplished with the model of a NACA 4415 wing. The model was equipped with a full span adjustable flap and three sets of end and center plates. Ground boards were place in the tunnel to simulate the earth's surface. Five different heights of the model above the ground boards were selected to represent in and out of ground effect regimes. Data were collected for forces and pressures on the model and on the board. The graphical representation of results displayed the effects of changing model parameters versus force, moment and pressure coefficients. These conclusions were compared to theory and other literature for correlation. Results were conclusive. The effects of center plates and the variation of plate size were negligible. The presence of the set of end plates was beneficial near the surface but was negligible out of ground effects. The height of the model above the board produced noticeable differences in results. Angle of attack was shown to have a marked influence along with flap angle. Pressure plots also appeared to provide a method of predicting the amount of lift produced.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1987
- Accession Number
- ADA182570
Entities
People
- Lawyn C. Edwards
Organizations
- Air Force Institute of Technology