1、英文原文Simulation Model of Gas Migration and Hindering in Underground Tunnel Based on LBMAbstractA simulation model of gas migration and hindering based on separated multi-component Lattice Boltzmann Method (LBM) is put forward in order to research gas migration and accumulation on underground tunnel a
2、nd to prevent major accident in mines. The tunnel is separated into some relative regular blocks through the separated & coupled algorithm and the multi-component LBM is adopted. The gas emission sources are disposed randomly. When gas passing tunnel, the gas emission sources are propagated together
3、 with original gas flow. At the same time, the obstacles are set up randomly in tunnels. Using the gas hindering model the changing condition of direction and gas concentration is researched when the gas encountering obstacles, then a powerful tool that can control gas migration and accumulation is
4、provided.Keywords: computer simulation gas migration and hindering multi-component Lattice Boltzmann Method; separated-coupled algorithm; coal mine I IntroductionUnderground tunnels are complex and the space of activity is narrow as the increasing of the underground mining activity. There are many g
5、as emission sources in tunnels. When gas gushes into underground tunnel, staff evacuation is difficult and major accidents occur. There are some obstacles in tunnel such as: mining cars, belt conveyors and air doors. If changing condition of direction and gas concentration are predicted when gas enc
6、ountering obstacles, then prevention strategy can be made scientifically and losses of gas disasters decrease. A simulation based on Lattice Boltzmann Method (LBM) is provided to research the law of gas migration and hindering in coal underground tunnel.Some researches has researched gas flow in und
7、erground mine. Reference 1 established a 3D math model for gas concentration distribution, and then analyzed law of the gas concentration and migration in underground tunnel. Reference 2 put forwarded solving this problem by stratified flow theory. Reference 3 analyzed the phenomena and characterist
8、ics of gas adverse current in underground tunnel flow, and provided dimensionless differential equations of gas flow and obtained similar parameters by the similarity principle. Up to now, many researches are based on experiment, while experiment is expensive and time consuming and has not long pred
9、iction. Especially the gas emission sources is changed constantly, it is more difficult to understand the law of gas flow according to on-site data by practical observation. Computer simulation is a good method to solve this problem.LBM has been developed into an alternative and promising numerical
10、technique of Computational Fluid Dynamics (CFD) in recent years 4. This method can be either regarded as an extension of the lattice gas automata or as a special discrete form of the Boltzmann equation from the kinetic theory. Unlike conventional numerical schemes based on the discretization of part
11、ial differential equations describing macroscopic conservation laws, the LBM is based on solving the discrete-velocity Boltzmann equation in statistical physics. It describes the microscopic picture of the movement of particles in an extremely simplified way. While at the macroscopic level, it gives
12、 a correct average description. The obvious advantages of the method are parallel in nature because of the locality of particle interaction and the transport of particle information, and are flexible in geometry because of the easy implementation of complex boundary conditions and complex properties
13、 of a fluid system.II MODEL OF GAS MIGRATION AND HINDERING IN UNDERGROUND TUNNEL BASED ON LBM AConstruction of Underground Tunnel ModelUnderground tunnel in underground coal mine is a network structure, as is showed in Fig.1. Underground tunnel branches are divided into same lattice when use LBM to
14、simulate. Every lattice can use some complex indexes such as concentration, speed and pressure to describe. When gas gushes into underground tunnel in somewhere in underground coal mine, high concentration gas occur. Gas emission strength is described by entrance concentration. At the initial time t
15、0, high concentration gas is produced. Because there is air flow in emission position, forced convection is produced, then gas flow into underground tunnel at initial speed v0, pressure p0, concentration C0. In moving process, speed and pressure of gas flow decrease gradually by the hindering effect
16、 of underground tunnel boundary while gas concentration of gas flow increase along gas moving direction. When gas moves to a bifurcation, it will bifurcate.In simulation process, underground tunnel is set in same time clock. As time elapse, the concentration, pressure and speed of every lattice will increase, they show gas propagation in underground tunnel. The errors of concentration in pre-and post in all lattice of the network are calculated to judge whe
