Investigation and Mechanical Behavior Analysis of Automatic Deformable Deflector Based on Smart Materials

Key words:  deflector  smart materials  mechanical behavior  simulation  loss coefficient

Abstract:

Smart materials, especially shape memory composites and 4D printing materials, are widely used in aerospace. Deflectors are essential equipment in wind tunnel construction. Classical deflectors are made of metal materials and have a relatively high structural weight. The deflector made of smart material has the advantage of being lighter in weight compared to classical structure, and it could change the bending angle of the deflector structure under external excitation. In this study, the corresponding mechanical property test and finite element simulation of the smart material are carried out, and the deflector made of smart material is further studied and analyzed. Maxwell viscoelasticity model for the material is established, and relevant parameters are obtained through stress relaxation test fitting. According to relevant parameters and literature, finite element simulation of intelligent deflector structure is carried out. The pressure loss coefficient, airflow deflection angle, and velocity uniformity are studied. The numerical model of the minimum pressure loss coefficient is established with reference to the relevant data, and the formula for calculating the optimal upwind radius of the deflector is obtained. Combined with the numerical simulation results of the flow deflection angle and velocity uniformity of the flow field, it provides a reference for the selection of the size of the deflector.