A NUMERICAL METHOD FOR DISCRETE FRACTURE NETWORK MODEL FOR FLOW AND HEAT TRANSFER IN TWO-DIMENSIONAL FRACTURED ROCKS

For the problem of flow and heat transfer in fractured rocks,two hypotheses of heat exchange between rock matrix and fluid in the fracture are compared analytically.It is found that the same result will be obtained for that the fracture aperture is small in general.A discrete fracture network model is realized in commercial finite element software COMSOL for the computation of flow and heat transfer in fractured rock.Both fluid flow and heat transfer in rock matrix and fracture can be calculated in this model,as well as fluid and heat exchange between them.The results are validated by comparing with analytical solutions.Finally,the model is used to simulate a randomly generated fracture network to study the characteristics of flow and heat transfer in fractured rock;and reasonable results are obtained.