Ground Effect on a Lift Generating Body

Abstract

Ground effect is the increase of lift and reduction of drag, on a lift generating body in flight at heights of one chord or less above the ground. This beneficial effect has been harnessed for development of ground effect vehicles since in the early 1900s. To date, large-scale commercial production of ground effect vehicles has not taken place. The literatures consists of investigations reporting ground effect with increased lift and reduced drag, but do not discuss the mechanisms behind changes in lift and drag. Most ground effect research was carried out with the image method or the flat plate method to simulate the ground. Only one recent work used the moving belt method to simulate the ground. Due to limited laboratory resources in this study, wind tunnel experiments were carried out with a flat plate simulating the ground. Pressure distributions, lift and drag forces were obtained from a finite wing of NACA 4415 section with aspect ratio 2.51. The experiments were carried out at positive angles of attack from 0-8 deg in ground effect.