Numerical Prediction of Flow Induced Vibrations in Underflow Sluice Gates

Abstract

Vertical rising underflow weirs commonly manage the water levels of small rivers and supply currents. The flow underneath the sluice gate provokes unsteady flow structure generation, which causes structural loads on the weir. The suspension of the vertical rising weirs responds. The resulting vibrations and oscillations of the gate at its eigenfrequency can cause additional or amplification of the flow structures, closing the feedback loop. Resonance can lead to significant damage and even fatigue of the weir. We simulate the multiphase flow numerically using the large eddy simulation approach to investigate such critical conditions and impose the unsteady loads as boundary conditions for structural calculations. The coherent flow structures induced at the leading edge of the sluice gate interact by a leap-frogging phenomenon, causing upstream running surface waves to clash against the sluice gate. The structural computations reveal that the low-frequency loads induced by these water waves due to vortex leap-frogging are dominating.