Research On The Influence Of The Roof Opening On The Hydraulic Properties Of The Unpressurized Tunnel Intersection Area

Although the cross pressureless tunnel is very small in the construction of water conservancy projects in my country,problems such as the flow pattern is disordered,the turbulence is mixed violently,the flow velocity is too fast,and the mixed free-surface-pressure flow etc.may affect the entire Engineering safety and bring certain hidden dangers to normal operation.Therefore,in order to effectively ensure the safety and normal operation of the water conservancy project,it is necessary to carry out research and analysis the hydraulic characteristics of the relevant water flow at the intersection of the crossing pressureless tunnels.At the same time,there will be cross pressureless tunnels in the urban drainage system.Therefore,analyzing the impact of the hydraulic characteristics of the water flow at the intersection on the pressureless tunnel is of great significance to the infrastructure construction.This paper mainly uses SolidWorks to carry out 3D simulation modeling of the cross pressureless tunnel in the actual project,and uses the software ANSYS ICEM to mesh its 3D modeling model,and uses ANSYS FLUENT to carry out the 3D simulation calculation.The discrete turbulence solution analysis method uses the finite volume method,the turbulence discrete model uses the Realizable model,the PISO algorithm is used as the solution method,and the gas-liquid two-phase flow solution method uses the VOF method.Tecplot is used for subsequent processing of the calculation result data.The main research contents of this article are:(1)Summarize the research results of both domestic and foreign previous scholars and experts;(2)Explain the theoretical basis of numerical simulation,and introduce basic theories such as mathematical models,calculation methods,and control equations of numerical simulation calculations;(3)First use the Solidworks software to establish a generalized model of the cross pressureless tunnel with the intersection angle ?=30°,and then use the ICEM software to mesh the model,give the initial conditions and boundary conditions of the model,and finally use the software FLUENT simulates and simulates the cross-pressure-free tunnel model under different flow conditions,and compares the obtained numerical simulation calculation results with physical test data,which verifies the scientific correctness and reasonableness of the numerical simulation method used in this article Sex(4)Research and analyze the flow rate,pressure,water depth,floor pressure head and other hydraulic characteristics of the flow velocity,pressure,water depth,and floor pressure head of the cross section of the cross-pressureless tunnel with different opening positions,different opening areas,different opening spacings,and different openings with the same flow rate.Draw relevant conclusions.