DIRECT NUMERICAL SIMULATION OF AEROELASTIC VIBRATIONS OF A HIGH-ASPECT-RATIO ROD FOR MODES CLOSE TO RESONANCE MODES

This paper describes a numerical simulation of vibrations of an elastic rod whose height is significantly greater than its transverse dimension and which is placed perpendicularly to the external flow and rigidly mounted on a substrate. Simulation is carried out in the ANSYS software package using bidirectional coupling technology. The natural frequencies and vibration modes of the rod are calculated. The airflow structure is analyzed and its features in the vicinity of the model are described. The process of exciting the vibrations of an elastic rod under the action of an external flow is investigated and its stress-strain state is determined. Vibration modes in the direction of an incident flow and in the transverse direction are determined. It is shown that, if the first natural frequency and the vortex shedding frequency reach close values, the amplitude of the rod vibrations in the transverse direction sharply increases to a value approximately equal to 0.06 of the rod height, which is followed by natural vibrations with a constant amplitude in the transverse direction and variable amplitude in the direction of the incident flow.