A Study On Seepage Characteristic Of Rough-walled Fractures Based On Lattice Boltzmann Method

Lattice Boltzmann Method to simulate the seepage field of rock fracture,compared with the traditional numerical simulation has natural parallel characteristic,simple boundary condition processing,program is easy to implement,can get a clear physical picture and other unique advantages.Through the JRC values generated method established within a certain range of joint roughness coefficient JRC two-dimensional anastomosis of rock mass fracture structure;Through the middle point interpolation method to generate the JRC values within a certain range of the three-dimensional structure of rock mass fracture surface.Based on lattice Boltzmann method(LBM),set up the gateway for nonequilibrium extrapolation format,up and down the surface of rock fracture is a standard format rally rebound,mirror or periodic boundary processing method,simulation of rock fracture seepage model is established.By C++ programming to realize the lattice Boltzmann method to simulate and verify the classic poiseuille flow,was calculated under different JRC value rough fracture surface seepage features,discusses the joint surface roughness coefficient JRC,the size of the pressure difference and the influence of crack width of linear flow state.In this paper,the main work is as follows:(1)Using rough on the surface of the single fracture rock mass JRC2D numerical method.This method need only in the source program of Visual Studio to use suchai,bi,ci di four parameters and can generate a certain roughness of single fracture,the four parameters of ci and di these two parameters can rise to control the function of the relative fluctuation amplitude Ra value;While the elongation value of R by such ai,bi,ci di decide together four parameter values.As long as the control of these four simple parameters can generate a specific journal register value of two-dimensional rough fracture surface rock joints.The method is of simple operation,strong operability,it has a broad development prospects.(2)Through the control variable method,the research must be joint roughness coefficient JRC seepage characteristics of rock fracture and pressure difference of delta function relationship between P and gap width b.(3)Joint roughness coefficient and cubic theorem into inverse correlation between the index value of n linear function relation.When the fissure structure surface is rough,the consumption of the kinetic energy of the flow field around,so traffic will reduce,run back to get the value of n will also drop,led to the birth of the cubic seepage.In this paper,using the method of Lattice Bolztmann Method is verified poiseuille flow;Using Lattice Boltzmann Method to study the 2D and 3D rock fracture seepage in both cases,the research not only has guiding significance for practical engineering application,and further deepens our understanding and awareness of rock fracture seepage...