NUMERICAL SIMULATION OF FLOW PATTERN OF CAVING FLOW FIELD IN THE INHOMOGENEOUS GOAF WITH ARBITRARY SHAPE

To study the variations of airflow in the goaf flow field withvarious boundary conditions, a finite element numerical modelis established tocompute the flow pattern of caving goaf based on flowequation for air leakage in heterogeneous porous media. Combined within-situ cases, the seepage flow patterns of air leakage in goafs withcomplicated shapes are described, and anaccurate graph distribution solution of flow pattern is given. Flowpattern computation is carried out by using a modified function of streamfunction Laplace equation proposed by the author, and the flowfields of heterogeneous goafs with complicated shapes and along theboundary direction can meet the condition of orthogonality offlow net, and at the same time the orthogonality can be controlled by theprecision of split meshes. A conclusion is drawn that the air leakageintensity of goaf along the caving uncompacted zones around solid wallboundary is relatively large, namely, the air leakage intensity of two ends ofworking face is large, and the flow lines can be extended to the deep parts ofgoaf.