Aerodynamic Performance of a Wing in Ground Effect Using the PANAIR Program.

The primary objective of this thesis is to correlate computed theoretical data with experimentla data for wings in ground effect. This investigation uses the PANAIR computer program--a higher-order panel method to predict the lift and drag characteristics of an aspect ratio two wing, with and without endplates, operating at low speed in ground effect. The effects of altitude, trailing edge flap deflection and angle of attack are considered. Numerical results are compared with subsonic wind tunnel experimental data. For both the numerical and experimental methods, the image model technique is used to simulate ground effect. Excellent agreement between numerical results and experimental data is achieved for the wing without endplates down to low (approximately 10% of wing chord) altitudes. For the wing with endplates, numerical results are in good agreement with experimental data for altitudes greater than approximately 20% of the wing chord. PANAIR results diverged from experimental data at lower altitudes because the model did not attempt to account for spanwise flow between the bottom of the endplate and the ground, and other viscous effects which tend to become dominant. These include a static pressure increase beneath the wing and wake distortions behind the configuration. Keywords include: Aspect ratio, WIG(Wing in Ground Effect), Life coefficients, Life drag ratio, and Inviscid theory.