Influence of main and outer wings on aerodynamic characteristics of compound wing-in-ground effect

Abstract

A practical mathematical model with low computational time and good accuracy is applied to investigate the aerodynamic characteristics and static height stability of the compound wing-in-ground effect (WIG). The compound WIG consists of a main wing with low aspect ratio and an endplate, and an outer wing with high aspect ratio. To validate the present mathematical model, a numerical simulation is performed so that numerical results had a good agreement with the experimental data. The analysis shows that the main wing is useful in the extreme ground effect zone and the outer wing enhances performance of the compound WIG in the weak ground effect zone. In order to satisfy the static height stability of the compound WIG it is evaluated by Irodov's criterion. Influence of junction position of outer wing on the main wing is investigated on the static height stability of compound WIG. A comparison of Irodov's criterion shows that static height stability improves with moving the outer wing position backward into the trailing edge of the main wing and this led to a decrease in the tail area. The proposed mathematical model could be appropriate for aerodynamic optimization of WIG crafts with the compound wing.