The Research On The Law Of Methane Gas Flow And The Structure Of Interspaces In Surrounding Rock Of Coal Goaf

For the more accurate understanding and summarizing the law of gas flow in coal goaf,deepening our understanding of the law of evolution of the structure of pore and fractures,studying the contact of transfusion and the above, the paper stated the extensive content ofliterature material, used the rock mechanics\fractal rock mechanics\mechanics of fluids in porousmedia\fracture mechanics\finite element analysis and some other theory of cross subject, anddeduced the formula in the new forms or the extension of certain formula, adopted the method ofcombining of the theoretical derivation and numerical simulation, simulated the law of gas flowin coal goaf under the condition of adding highly located drainage roadway or not with thesoftware of FLUENT, let the experience known and summary in character of it in the past canhave a numerical expression in a new situation.The paper mainly get the following conclusions:1. It gave the relationship between the fractal dimension and the critical damage stress;deduced the formula of the crack growth acceleration under the influence of stress wave, andgave the dynamic fracture criterion of crack in form of rotor angle; derived a expression of thepermeability coefficient in expression of concentration degree or fractal dimension of fracture;derived a expression of the permeability coefficient of gas flow with the cubic law of transfusionin parallel fracture, the expression of the permeability coefficient; derived the gas diffusioncharacteristics under the condition of wind current (not static) by the expression of diffusionfluxes of gas molecular.2. It used the parabolic expression of content of gas to derive newly the effective stressprinciple of porous media and expansion stress and expansion linestrain of coal and rock; and itgave the seepage field equations of fluid structure coupled of porous medium with the sameexpression.3. It integrated the formulas of total flow about the gas flowed into the drilling around andgot the last solution.4. It simulated the law of gas flow in coal goaf under the condition of adding highly locateddrainage roadway or not, and analyzed the reason of according with or deviation from practice.