بررسي جريان غيرخطي در شكستگي هاي سنگي با ديواره زبر

Evaluation of Non-linear Fluid Flow Through Rough- walled Fractures

In many geological structures, the matrix permeability is negligible and the fractures are the main flow paths. The fluid flow and particle transport through rock fracture are increasingly important research topics mainly to the demands for design, operation and safety assessments of underground/ surface constructions. In this paper, single-phase fluid flow through a rock fracture is studied. Computational domain for an artificial three-dimensional fracture is generated and used for numerical fluid flow simulations. Both laminar and turbulent flow simulations are performed by using finite element method for a wide range of inlet velocities. The calculated average pressure drops, between consecutive vertical sections are compared to describe the flow rate dependant pressure drop. The simulations results show that; (i) the predicted static pressure drop for turbulent flow simulation was roughly 3ʹ/. to 17% more than laminar simulation at Reynolds number of 4.5 to 89.5, respectively, and (ii) the Forchheimer law is fitted very well to flow simulation results and critical Reynolds number of 15 is suggested. KEYWORDS: Non-linear fluid flow, Fluid flow simulation, Turbulent and laminar flow, Forchheimer law, Rock fractures.