Experimental Research And Numerical Simulation Of The Impact Of Pipe Velocity On Orifice Discharge And Orifice Inflow

In water distribution system,the calculation of pipeline leakage and intrusion is the basis for assessing the risk of pipeline leakage and groundwater intrusion.In fact the traditional orifice outflow formula is not suitable for pipe orifice outflow.In this paper,the transverse flow velocity in the pipeline is studied.Firstly,taking full account of the pipe velocity on the pipe orifice outflow,the traditional orifice outflow formula is no longer applicable to the existence of pipe flow velocity conditions.The experimental results show that the effect of pipe velocity on the flow of the orifice.And the influence extent of the pipe velocity in the tube on the outflow of the orifice was analyzed.Secondly,by analyzing the change of orifice shrinkage area,the velocity of orifice discharge was calculated,and the main influencing factors of orifice outlet flow were studied.The influence law of orifice outlet flow factor under different pressure was studied.By comparing the flow curves of vertical and horizontal orifice,the influence of flow velocity on the outflow of the orifice is described.Thirdly,by comparing the orifice outflow with inflow,the similarities and differences between inlet and outlet flow are analyzed,and the mechanism of the influence of the flow velocity on the outflow flow was systematically described.Lastly,the numerical simulation software was used to simulate the experiment,and the pressure profile and the velocity profile were analyzed.The results were explained in depth by theoretical analysis.The experimental results show that both the outflow and the inflow of the pipe are affected by the transverse velocity,the effect mechanism is the inertia of the fluid,the velocity coefficient of the orifice is linear with the velocity of the pipe,the area of the orifice shrinks linearly.The experimental analysis shows that the outflow and inflow are affected by the pipe flow velocity,and the main reason of the effect was the inertia of the role of the fluid.