Experimental Investigation On Flow-Induced Vibration Of Rudder-Wing System

The flutter problem first appeared in the aviation field.In recent years,with the development of marine vehicles and the policy of maritime power,the flutter problem of the hydrofoil has gradually received attention.Similar to the case of the wing,improperly designed rudders can induce flutter.In addition to the classic flutter,the low-speed rudder will also experience weak flutter.Its hazard does not cause structural damage to the rudder system,but induces noise in the water,thereby damaging the quiet navigation of the underwater vehicle.Although the vibration theory and corresponding experimental methods for airborne structures such as aircraft and bridges are quite mature,the theory of flow-induced vibration of the rudder wing system and the corresponding experimental problems are still new to China’s hydrodynamics.Therefore,the topic of this paper has important scientific significance and engineering value.In this thesis,the similarity theory of flow-induced vibration of rudder wing system is established based on the theory of hydroelastic mechanics,and the design,manufacture and installation of test device,rudder-wing model and spring system are expounded.The sensors used in this paper—acceleration sensor,inclinometer and fiber grating are introduced.The test flow and data processing method are described in detail.A water tank was designed for the natural frequency of the rudder-wing system and a natural frequency tap test was performed.Experiments were carried out on three different rudder-wing models,and the acceleration sensor,inclinometer and fiber grating test results were analyzed.The test results show that as the angle of attack increases,the critical flutter speed decreases.At the same spring and angle of attack,the critical flutter speed is reduced when the rudder shaft is moved forward and the end plate is added to the bottom of the wing.The forward position of the rudder and the addition of the end plate below the wing can significantly weaken the torsional vibration amplitude of the rudder,but have less influence on the wing vibration.