Research On The Response Of Hydraulic Elements To Bed Deformation For Discharging Under The Sluice Gate And Planar Impinging Jets

There is always certain deformation on the flow boundaryin nature and engineering.Simulating the boundary deformation process precisely and working out the response of hydraulic characteristics to boundary deformation, are important research topics in the field of hydraulics and river dynamics. The discharge under the sluice gate and the planar turbulent impinging jets are practical in water conservancy, transportation and other fields. So far lots of conclusions have been drawn on them by experiments and numerical simulation including the process of boundary deformation and the flow characteristics. However, there is no overall and systematically research which focuses on the corresponding adjustment of hydraulic characteristics in the process of boundary deformation. Therefore, theoretical analysis and numerical simulations are applied in this article based on existing experiment achievements. The main achievements in this article are listed as follows:(1) A calculation method of mechanical energy loss for the rapidly varied flow region and the gradually varied flow region of discharge under the sluice gate is proposed based on the mechanical energy equation for total flow in open channels.(2) The discharging under the sluice gate is simulated refinedly through closing the Reynolds-average equations by Reynolds Stress Model and reflecting the effects of granular mixtures on flow in the boundary deformation region by the revised wall function. According to the simulation results, hydraulic characteristics in the rapidly varied flow region and the gradually varied flow region such as mean velocity, mean pressure, turbulent flow energy, mean wall shear stress and so on are analyzed respectively. Besides,how the corresponding characteristics including the discharge, the mechanical energy loss for total flow and so forth vary with the process of boundary deformationin of discharge under sluice gate is obtained. The results show that:1) the discharge responses lightly to the boundary deformationwhile the mechanical energy loss for total flow declines with the boundary deformation; 2) The horizontal distance of the reattachment point and the maximum scour depth point reduces synchronously and gradually and tends to be stable along with the scouring time.(3) The vertical planar impinging jets are simulated refinedly with the mentioned method and the response of hydraulic characteristics such as meanpressure, flow entrainment, the mechanical energy on the jet axis on bed deformation on the shock surface are analyzed The results show that:1) with the boundary deformation, the mean pressure decreases while the mechanical energy loss on the jet axis increases synchronously and tends to be stable; 2)along with the boundary deformation progress, flow entrainment at the front of the vertical planar impinging jets resembles the flow entrainment of the free jet but decreases sharply near the local scouring hole.(4) The planar oblique impinging jets are also simulated refinedly based on the mentioned method and how the mean pressure and mean wall shear stress on the shock surface response to the boundary deformation and the various incident angle are analyzed. The results show that:1)The mean pressure near the impact point increases with the increase of incident angle and peaks when,the planar oblique impinging jets comes to the vertical jets; 2) The mean wall shear stress near the impact point increases with the increase of incident angle and peaks when the planar oblique impinging jets comes to the vertical jets.