Intercoupling aeroelastic stability topology optimization for the design of bend-twisted hollow blade in a turbomachinery cascade

Aeroelastic stability of fan blades is a very important problem in the design of current aero-engines. For the hollow fan blade, the hollow region not only reduces the mass of the blade but also affects the aeroelastic stability. To achieve good aeroelastic stability and lightweight of the bend-twist coupled hollow blade, an intercoupling aeroelastic stability topology optimization method is proposed. The aeroelastic stability is considered as the constraint function, and the material layout in the hollow region of the blade is designed in the intercoupling aeroelastic stability topology optimization method. The sensitivities of the frequency and flutter boundary are derived. The flutter boundary of the hollow blade designed through the intercoupling aeroelastic stability topology optimization method will be improved. A hollow blade is designed by the proposed method to validate its effectiveness. At the design point, the cascade composed of the hollow blade designed by the intercoupling aeroelastic stability topology optimization method is aeroelastically stable at each nodal diameter, which verifies the feasibility of the intercoupling aeroelastic stability topology optimization method and the validity of the constraint function of aeroelastic stability.