J. Sodja

Design and Testing of Aeroelastically Tailored Wings Under Maneuver Loading

The goal of the present paper is to provide experimental validation data for the aeroelastic analysis of composite aeroelastically tailored wings with a closed-cell cross-sectional structure. Several rectangular wings with different skin thicknesses and composite layups are designed in order to minimize the root bending moment under maneuver loading using an aeroelastic analysis framework that closely couples a geometrically nonlinear beam model to a vortex lattice aerodynamic model. The globally convergent method of moving asymptotes is used to derive an optimized layup for the tailored wings. In addition, a quasi-isotropic wing is analyzed to serve as a reference. Both the tailored wings and the quasi-isotropic wing are manufactured and tested structurally and in the wind tunnel. In the wind tunnel, aerodynamic forces and moments and wing deformation are measured to provide experimental validation data.

Design of a flying demonstrator wing for manoeuvre load alleviation with cruise shape constraint

Application of the aeroelastic framework developed at Delft University of Technology to a design of the tailored composite wing for a flying demonstrator is presented in this paper. In the design process the structural mass of the wing is minimised including a cruise shape constraint. Introduction of the cruise shape constraint is explained as well as a number of other important design requirements which were imposed in order to obtain a feasible and flight worthy design. The effect of the cruise shape constraint is investigated by performing a comparison study. For this purpose two wing types were defined: the reference wing and the tailored wing. The difference between the two wings is in the laminate definition comprising each wing. The reference wing was designed with symmetric-balanced laminates, while symmetric-only laminates were used for the tailored wing. The comparison was performed in terms of laminate stiffness and thickness distribution along the span, jig twist, and the aeroelastic response. Elastic deformations, aerodynamic load distribution and wing root loads are compared within the scope of aeroelastic response.

High- and Low-Fidelity Investigations of Flexible Propeller Blades

Highand low-fidelity fluid-structure interaction analyses of flexible propeller blades are compared in this paper. High-fidelity fluid-structure interaction analysis are performed using coupled computational fluid dynamics and computational structural dynamics commercial codes, whereas low-fidelity analysis are based on coupled extended blade element momentum model and nonlinear beam theory. Three selected flexible propeller blade geometries are analyzed: straight, backward swept, and forward swept blades. The backward swept and forward swept blades are designed to emphasize the influence of the blade flexibility on the blade performance. A straight blade was selected in order to serve as a reference. In the course of the study, integral thrust and breaking power as well as their respective distributions along the blades are compared at different advancing ratios. Blade deflections are also analyzed.