Steady-Suction-Based Flow Control of Flutter of Long-Span Bridge

Jian Zhan,Huan Liu,Dabo Xin,Hongfu Zhang,Zhiwen Liu,Jinping Ou

doi:10.3390/app10041372

Jian Zhan, Huan Liu + Show 4 more

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https://doi.org/10.3390/app10041372

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Abstract

The present wind tunnel study focuses on the effects of the steady-suction-based flow control method on the flutter performance of a 2DOF bridge deck section model. The suction applied to the bridge model was released from slots located at the girder bottom. The suction rates of all slots along the span were equal and constant. A series of test cases with different combinations of suction slot positions, suction intervals, and suction rates were studied in detail for the bridge deck model. The experimental results showed that the steady-suction-based flow control method could improve the flutter characteristics of the bridge deck with a maximal increase in the critical flutter speed of up to 10.5%. In addition, the flutter derivatives (FDs) of the bridge deck with or without control were compared to investigate the fundamental mechanisms of the steady-suction-based control method. According to the results, installing a suction control device helps to strengthen aerodynamic damping, which is the primary cause for enhanced flutter performance of bridge decks.

Highlights

Bridge flutter is a catastrophic dynamic aeroelastic phenomenon that occurs due to interactions between wind and the vibrating bridge deck and can induce a total structural collapse
To verify the positive effect of the steady-suction control on the bridge flutter performance, two types of information should be collected: (1) the geometric information of the model and (2) important aerodynamic parameters, including the flutter derivatives (FDs) and critical flutter speed obtained through the FDs
Wind tunnel experiments were conducted to prove the feasibility of the steady-suction-based flow

Summary

Introduction

Bridge flutter is a catastrophic dynamic aeroelastic phenomenon that occurs due to interactions between wind and the vibrating bridge deck and can induce a total structural collapse. When the inflowing wind is faster than the critical flutter speed, the bridge girder structure extracts energy from the free stream flow for a divergent response. Flutter is one of the most important factors in the design of a long-span bridge and must not occur during its life cycle. Owing to the increasing bridge span, the flutter problem has become increasingly prominent, and new wind-resisting strategies and techniques are necessary. Alternative approaches have been presented for cases where the parameters of the structure itself cannot meet the design requirements (i.e., the critical flutter wind speed) of the structure. These are classified into mechanical strategies and flow control strategies. Nobuto et al [1]

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