Simulation And Analysis On The Flow Field Inimpeller Stirred-tank In Test System For Permeability Of Fractured Rcok Specimen

In order to complete the project supported by national basic research program of china(no. 2013CB227900), the second research group of the project put forward a task designing a system for measurement of the permeability parameters of fractured rock taking water and sand as penetrant. It is suggested that the sand concentration don’t change with time and approach the one at the fluid outlet in the vessel. We were assigned to have the computer-assisted design of the mixing tank. It is the major content to simulate the water and sand two phase flow fields(WSTPFF). In the current thesis, the Pro/E、ICEM and FLUENT are used synthetically to conduct the simulation of flow fields, the effects of the rotating speed of the impeller, the distance of the impeller off the container bottom and natural height of sand pile were analyzed. The parameter optimization of the mixing tank have been carried out. Conclutions are given as follows:(1) According to the design specification, the project design of the test systerm has been accomplished on the basis of functional decomposition and composition.(2) The impeller diameter, the hight of impeller,the number of blades, rotating speed of the impeller, the diameter of vessel, the position of both the pump inlet and backflow mouth, the distance of impeller from bottom of container, and some other parameters of the mixing tank have been determined by the computer aided design.(3) Under the simplification of the configuration, the governing equations of WSTPFF in the mixing tank have been established on the basis of simplification of the configuration by using on the basis of k -e bi-fluid trubulence model.(4) Multiple reference frame method was used to process the stir zone, and finite volume method was used to complete the discretization of governing equations,and SIMPLE algorithm was used to the iterative operation. The convergence of the algorithm is verified by residual steps curve of physical quantities.(5) The effects of the rotating speed of the impeller, the distance of the impeller off the container bottom and natural height of sand pile on WSTPFF were analyzed by the comprehensive use of Pro/E, ICEM and Fluen.(6) The parameters of mixing impeller under the different natural height of sand pile have been optimized by the simulation of WSTPFF.The research results can provide references for researchers worked at coal mining to have computer-assisted design of test system or assembly of rock permeability.