عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Practical employment of high angular velocity-centrifugal force field in nuclear industry, especially in separation of heavy isotopes in both industrial scale fuel production and laboratory practices, is obvious. Thermo-hydraulic differential equations of such a flow field due to ultra-high swirl velocity and also high compressibility of low mass content of gas injected into the system are very complicated and closely coupled. Thus, the analytical solution of these equations necessitates making a few assumptions. In this study, the numerical solution are conducted by the CFD approach and the finite volume method is used to evaluate assumptions of the analytical solution and to survey effects of removing these assumptions on the main variables of flow field. For this purpose, among available analytical methods to solve the governing equation, the one with the least possible assumptions is employed. The most important points in the procedure of conducting this solution are studied from the basic equations to the end and on this basis the assumptions are gathered under four titles. Then, the procedure of testing these assumptions in the FLUENT software is presented, which necessitates programming. Then the results are compared and validate by the results of the analytical method. In the next step, on the basis of consecutive elimination of the four assumptions, four different modes are defined. The novel and meaningful results obtained from the comparison of these four modes is the main incentive to present this article. This investigation, in addition to prove significant capabilities of the CFD approach for simulating this complicated flow field, clearly showed the reason of the long-term tendency toward this analytical analysis, despite its basic simplifying assumptions. Especially, with regard to the axial mass velocity due to contradictory and eliminating effect of consisting parameters.
 S. Villani, Uranium enrichment, Topics in Applied Physics, 35, Springer-Verlaq, Berlin, Germany (1986).
 D.R. Olander, The theory of uranium enrichment by gas centrifuge, Prog. Nucl. Energy, 48 (1981) 1-33.
 H.G. Wood, J.B. Morton, Onsager's pancke approxmiation for the fluid dynamics of a gas centrifuge, J. Fluid Mech, 101 (1980) 1–31.
 H.G. Wood, G. Sanders, Rotating comperssible flows withinternal source and sinks, J. Fluid Mech, 127 (1983) 299-313.
 M.D. Gunzburger, H.G. Wood, A finite element method for onsager pancke equation, Comput. Meth. Appl. Mech. Engng., 31 (1982) 43-59.
 R.J. Ribando, A finite-difference solution of onsager's model for flow in a gas centrifuge, Computers & Fluids, 12 (3) (1984) 235-252.
 I. Harada, Computation of strong comperssible rotating flows, J. Comput. Phys., 38 (1980) 335-356.
 L.D. Cloutman, R.A. Gentry, Numerical simulation of the countercurrent flow in a gas centrifuge, Los Alamos Nantional Labaratory Report, LA-8972-MS (1983).
 ANSYS, Inc. ANSYS fluid dynamics verification manual, Canonsburg, Pennsylvania, November (2013).
 D.A. de Andrade, J.L.F. Bastos, Thermal hydrodynamical analysis of a countercurrent gas centrifuge, Ann. Nucl. Energy, 25 (11) (1998) 859–888.
 V.D. Borisevich, O.E. Morozov, O.N. Godisov, Numerical simulation of bellows effect on flow and separation of uranium isotopes in a supercritical gas centrifuge, Nucl. Instr. Meth. Phys. Res. A, 455 (2000) 487-494.
 T. Kai, K. Hasegawa, Numerical calculation of flow and isotope separation for SF6 gas centrifuge, J. Nucl. Sci. Tech., 37 (2) (2000) 153-165.
 R. Vadi, Analysis of gas centrifuge flow by the means of fluent software, MSC. Thesis. Department of Nuclear Engineering, Beheshti university, Tehran, Iran, (2011).
 S.V. Bogovalov, V.D. Borisevich, V.D. Borman, V.A. Kislov, I.V. Tronin, V.N. Tornin, Verification of numerical codes for modeling of the flow and isotope separation in gas centrifuges, Computers & Fluids., 86 (2013) 177-184.
 R. Vadi, A. Zolfaghari, Flow field analysis in centrifugal force field and optimizing it on the basis of maximizing, system separation efficiency, In Proceedings of 18th Iran's nuclear conference, Yazd, Iran (2012).
 D. Jiang, S. Zeng, CFD simulation of 3D flow field in a gas centrifuge, In Proceedings of ICON 14, Miami, Florida, USA (2006).
 G.A. Bird, Molecular gas dynamics and the direct simulation of gas flows, Oxford Univ. Press, London (1994).
 A.A. Ganjaei, S.S. Nourazar, A new algorithm for the simulation of the boltzmann equation using the direct simulation monte-carlo method, J. Mech. Sci. Tech. 23 (2009) 2861-2870.
 A.A. Ganjaei, S.S. Nourazar, Numerical simulation of a binary gas flow inside a rotating cylinder, J. Mech. Sci. Tech. 23 (2009) 2848-2860.
 R.B. Bird, W.E. Stewart, E.N. Lightfoot, Transport phenomena, Wiley, New York, 2th Edition (2007).
 ANSYS, Inc., Ansys fluent V. 15.0 documentation Manual, Canonsburg, Pennsylvania, November (2013).
 L. Zarkova, P. Pirgov, Transport and equilibrium properties of UF6 gas, Phys. B: At. Mol. Opt. Phys., 28 (1995) 4269-4281.