Analysis on the Aeroelastic Stability of Open Cylindrical Shells in Subsonic Airflow Using the Theoretical and Two-way CFD/CSD Coupled Methods

The aeroelastic stability of an open cylindrical shell in subsonic airflow is analyzed. The equation of motion of the open cylindrical shell whose one surface is subjected to the subsonic airflow is established based on the Donnell shell theory and transformed into ordinary differential equations using Galerkin's method. The linear potential flow theory is applied to derive the aerodynamic pressure. The natural frequencies of the aeroelastic system are obtained, from which the flow velocity for the open cylindrical shell under instability can be calculated. The effects of the material and geometric parameters on the critical instability velocity are discussed. Furthermore, the open cylindrical shell is modelled using the finite element software ANSYS. The time domain responses of the structure in subsonic airflow are calculated using the two-way CFD/CSD (computational fluid-structure dynamics) coupled method. From the results, it can be seen that with the increase of the thickness and elastic modulus of the shell, the critical instability velocity increases also. The open cylindrical shell with a smaller radius shows better aeroelastic properties than that with a larger radius. The time domain responses obtained by the CFD/CSD method are compared with those calculated by the theoretical method, and the results of these two methods have a good agreement with each other.