Aerodynamic characteristics of an elasto-flexible membrane wing based on experimental and numerical investigations

A flexible membrane wing is investigated with fluid structure interaction computations. An analysis for three Reynolds numbers is conducted at various angles of attack by means of the URANS TAU-Code and the FEM CARAT++ solver. The advantages of the flexible concept is highlighted by comparing the flexible geometry to its rigid counterpart. The flexibility and adaptivity of the membrane allow the wing to adjust its shape to the pressure distribution. Therefore a change in the geometry affects the aerodynamic properties, i.e. the lift and the drag, of the wing. For positive angles of attack, the airfoil’s camber increases, which induces a lift increase. The stall onset is postponed to higher angles of attack and the abrupt decrease in the lift is replaced by a gradual decrease of it. In the stall region, the flexible geometry offers a better lift-to-drag ratio as its rigid counterpart. Wind tunnel tests are conducted as well, establishing an estimation of the accuracy of the computations.