variavel0=<b>Roberto da Mota Girardi</b> - girardi@aer.ita.br Instituto Tecnológico de Aeronáutica (ITA)
<b>Abstract.</b> One of problems in the sky ship operation is the lateral force associated to winds in the transversal direction. In the case of the standard sky ship the lateral force has a great value due to the shape and dimensions of such aircraft. This problem can be minimized by changing the sky ship shape. A revolution elipsoid is one of these shapes and the aircraft looks like a circular wing . In this paper the numerical results obtained with a computational code, based on the panel method, are presented to solve the three dimensional flow over a revolution elipsoid. The pressure distribution on the aircraft surface as well as lift and induced drag forces and moments can be determined with such computational code. In order to verify the validity of such numerical procedure to the particular case of a circular wing, the numerical results are compared to experimental and analytical ones. The experimental results were obtained for a model made of wood and the tests were conducted for a Reynolds number equal to 4.0 x 105 . For a set of angles of attack ( a ), lift and drag forces are measured as well as the pitch moment. The pressure distribution (Cp) along the model symmetry plane (root chord) was measure only for a = 6 degrees. The theoretical results were obtained by using the small perturbation theory for a circular wing with zero thickness.
<b>Keywords.</b> panel method, circular wing, wind tunnel, three-dimensional flow.