基于较高流速流激振动的拦污栅结构优化OA

After the hydropower unit is put into operation,the detachment or fracture of trash rack bars may allow large debris to enter the flow passage of unit,seriously threatening the operational safety of units.Therefore,this study employs the finite element method to conduct numerical simulations of the flow field for the original trash rack structure,analyze the causes of its failure,and carry out structural optimization.The finite element simulation results indicate that the three bottom sections of the trash rack are prone to resonance failure under high flow velocity due to flow-induced vibration.The optimization design focuses on these three bottom sections.While maintaining the cross-sectional height and spacing of the bars,a fish-bellied double main beam structure is adopted,with the main beams and comb-type connecting plates aligned along the flow direction to increase the flow area and reduce vortex-induced vibration.Additionally,the bar cross-section is optimized from a rectangular to a double-rounded head shape to improve the flow pattern and minimize local vortices and stress concentration.Through a combination of theoretical calculations and numerical simulations,the interference frequency and natural frequency of the trash rack before and after optimization are analyzed,with the results from both methods being largely consistent.Furthermore,the head loss of the trash rack before and after optimization is calculated,showing a significant reduction in the optimized structure.The research results demonstrate that the optimized trash rack structure exhibits superior hydrodynamic characteristics and effectively resolves the issue of resonance-induced bar detachment.