Aiming at the problem that air-entraining vortices are prone to form during the bidirectional operation of the bidirectional side intake of a ship lock,which endangers the safe and stable operation of engineering projects,and to make up for the deficiencies of existing studies on the action mechanism and parameter optimization of vortex suppression measures under bidirectional working conditions,a systematic study on the vortex suppression mechanism and parameter optimization of bidirectional side intakes is conducted.On the basis of the generalized model of the bidirectional side intake for ship locks,the influence laws of the relative spacing of vortex-suppressing beams and the side wall distance on vortex evolution are systematically investigated via three-dimensional numerical simulation.The results show that when the relative spacing of vortex-suppressing beams decreases from 1.00 to 0.45,the maximum tangential velocity decreases by 51.65% and the water surface circulation constant reduces by 84.05%,and the improvement of vortex suppression effect slows down when the relative spacing is less than 0.55.When the side wall distance decreases from 2.5D (where D is the diameter of the outlet pipe) to 1.5D,the maximum tangential velocity decreases by 68.65%,and the water surface circulation constant reduces by 82.42%.The results of this paper reveal the synergistic vortex suppression mechanism of vortex-suppressing beams and side walls under bidirectional working conditions,clarify the optimal spacing of vortex-suppressing beams and the recommended side wall distance,and provide a scientific basis for the vortex suppression design of related projects.