THE EFFECTS OF THE PLANFORM SHAPE ON DRAG POLAR CURVES OF WINGS: FLUID-STRUCTURE INTERACTION ANALYSES RESULTS

The paper shows preliminary results of aeroelastic analyses of two half-wing models, having curved and swept planform, carried out at the Aerospace Section of the Department of Civil and Industrial Engineering of Pisa University. The curved planform causes a variable angle of sweep along the wing span, so, as demonstrated in previous papers regarding rigid models of wings, in the transonic flight conditions wave drag effects are strongly reduced. The present numerical comparison, between curved and traditional swept wing, includes the effects of structure’s deformability (the wings have the same aspect ratio). The effects of the planform shape on drag polar curves are confirmed (for fixed values of Lift Coefficient (CL) the reduction of Drag Coefficient (CD) reaches 7%-10%). Moreover the curved planform configuration improves the wing’s aeroelastic behavior: in the paper some results obtained by using Star-CCM+® 6.04.14 and Abaqus® 6.11 in “co-simulation” are summarized. As an example, adopting similar wing box metallic structures for the two half-wing models, for a fixed value of CL the reaction moments and stress values at the root of the curved wing are reduced by about 5÷8% with respect the data obtained for the traditional swept wing at the same flight conditions.