The Heat Flow Model Research On Underground Tunnel System Based On Lattice Boltzmann Method

In recent years,because there are more and more underground mine tunnel fire accidents which bring heavy losses to our country's property and people's lives,thus it is of great significance to research the heat flow on underground tunnel.However,in recent years the heat flow research on underground runnel is confined to the finite element and the finite volume method which solve complicated partial differential equations to deduce the Navier-Stokes equations and have poor satisfied simulating effect.In addition,experimental methods can be adopted.Yet it can not simulate the fire flow completely because there are complex and changeable actual conditions in underground tunnel.Therefore it becomes an important issue to design new model to simulate heat flow on underground tunnel.Lattice Boltzmann Method(LBM) is emerging in recent years and is studied by many scholars because it calculates without solving complicated partial differential equations and deals with the border easily.Based on Lattice Boltzmann Method and combined with fluid dynamics and thermodynamics,the paper mainly researches on fire accident which occurred on underground mine tunnel.Adopted velocity and temperature dual-distributed Lattice Boltzmann Method,it separated irregular underground tunnel into some regular blocks with Separated & Coupled Algorithm.It can simulate the spreading laws of heat flow on underground tunnel because the lattice is calculated simultaneously in the regular blocks and coupled in borders between each blocks.First,the heat flow model on underground tunnel based on Thermal Lattice Boltzmann Method is proposed.Various models and boundary treatment patterns are analyzed,then the heat spreading on straight tunnel are simulated.Secondly,the principle of Separated & Coupled Algorithm and based on it Dual-distributed Lattice Boltzmann Model is proposed.Tunnel construction and the method of separated block is adopted.Based on it,the underground tunnel is separated some regular blocks. Following,its temperature and velocity are simulated.Then,an effective way to evading heat flow and simulated result are adopted.Thirdly,the Spreading & Hindering Model is proposed because there are many combustibles and obstacles which may have an impact on heat flow in underground tunnel.Through simulating heat flow of actual tunnel,the spreading & hindering laws on heat flow of entire tunnel can be adopted. Next,based on analyzing the anti-wind means which existed in actual production and on anti-wind without wind tunnel,Anti-Wind Models with backup fan is proposed.The backup fan which can carry out anti-wind when the heat temperature reaches certain limit is turned on,which achieve good results in actual simulating.Finally,in the view of actual tunnel structure,the 3-Dimension Model on temperature and velocity dual-distributed Lattice Boltzmann Method is proposed which achieve better effect on simulating heat flow on actual tunnel.Considering with wind velocity and heat temperature,a number of spreading & hindering models in view of complex underground tunnel are proposed and actual tunnel can be simulated in various situations.And the heat flow spreading models on 3-dimension is explored and researched,which conducive to further study in depth.