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To study the fluidelastic instability(FEI) fluid force model, the FEI process controlled by the fluid damping mechanism was taken as the research object, and the fluid-tube interaction was simulated with one elastic tube in the middle of a normal-triangle tube array under a series of free stream flow velocities. A polynomial function was chosen as the fluid force model, the simulated fluid forces and the tube displacements were used to calculate the unknown coefficients in the fluid force model. The influence of the flow velocity on the fluid force model was introduced and the relationship between fluid force coefficients and inlet flow velocities was fit. A fluid force model related to tube displacements, tube velocities and flow velocities was obtained. The predicted FEI critical flow velocities with the proposed fluid force model were compared to the experimental data and numerical results given by literatures. The fluid force model, constructed with the proposed method based on numerical results and the given mathematical function, can capture the main characteristics in the flow tube array interaction, and reasonably predict the FEI critical velocity. [ABSTRACT FROM AUTHOR]

In order to solve the present river velocity measurement system which uses cable, and has low anti-interference ability, system flexibility and signal attenuation, this paper builds an intelligent river velocity acquisition system to realize automatic acquisition point velocity. The system uses the ZigBee network structure, and the control center computer is connected to ZigBee coordinator, flow velocity collection device connected to the ZigBee terminal, and at last realizes the velocity data acquisition and data transmission. The system realizes automatic elimination of propeller current error data with the analog time series of velocity data, and generates flow cross section measurement transformation matrix according to the flow velocity instrument layout information, so that the problem of the velocity data and the actual measured flow point matching is solved. System separates velocity data and data processing to improve the efficiency of experiment and data processing. Practice application shows that, the flow velocity collection system can meet the needs of large model of river flow velocity collection, the system is flexible and accurate. [ABSTRACT FROM AUTHOR]