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Exploration of Wall Thinning Degradation Mechanism in Double Elbow Pipe
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Abstract
The objective of this study is to simulate the heavy water flow in the double elbow pipe under flow accelerated corrosion (FAC) conditions. From the simulated results the existence of eddy structures and their mutual interactions are investigated. These eddies are responsible for the wall shear stress distribution and this distribution is an important factor in predicting the local regions of the pipe that are highly susceptible to FAC. The streamline portrait, exhibits the recirculation regions at the corners and at the downstream of the elbows. A detailed study about the reattachment length has been carried out at the preferred recirculation regions, in which the consequences of these regions lead to the high wall shear stress. The calculation of reattachment length and the distribution of wall shear stress, for Re ranging from 1e+2 to 2e+5 are carried out by increasing the distance between the upstream and downstream elbows. It is observed that the reattachment length is initially constant (laminar flow), then increased (transitional flow) and again became constant (turbulent flow) as Re was increased. The reattachment length decreased as the distance between the elbows was increased. The maximum value of wall shear stress occurred in the vicinity of elbows and on the opposite walls of the downstream recirculating regions of elbows.
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References
J. L. Singh, Umesh Kumar, N. Kumawat, Sunil Kumar, Vivekanand Kain, S. Anantharaman, A. K. Sinha, Flow accelerated corrosion of carbon steel feeder pipes from Pressurized Heavy Water Reactors, Journal of Nuclear Materials, Vol.429, pp. 226 – 232, (2012).
S. Roychowdhury, V. Kain, A. Matcheswala, A. Bhandakkar, Sigma phase induced embrittlement in titanium containing austenitic stainless steel tie-bars in a condenser, Engineering Failure Analysis, Vol. 25, pp.123-132, (2012).
J. M. Pietralik, B. A. W. Smith, CFD Applications to flow-accelerated corrosion in Feeder Bends, Proceedings of the 14th International Conference on Nuclear Engineering (ICONE-14), Miami, FL, Jul. 17–20, pp 89323, (2006).
K. Vivekanand, S. Roychowdhury, T. Mathew, A. Bhandakkar, Flow accelerated corrosion and its control measures for the secondary circuit pipelines in Indian Nuclear Power Plants, Journal of Nuclear Materials, Vol. 383, pp 86-91, (2008).
D.G. Kang, J.C. Jo, CFD application to the regulatory assessment of FAC-caused CANDU feeder pipe wall thinning issue, Journal of Nuclear Engineering and Technology, Vol. 40(1), pp.37-48, (2008).
J. M. Pietralik, Mass transfer effects in feeder flow-accelerated corrosion wall thinning, 18th CNS International Conference on CANDU Maintenance, Toronto, November 16-18, CW-33126-CONF-009(2008).
J. M. Pietralik, C.S. Schefski, Flow and mass transfer in bends under flow-accelerated corrosion wall thinning conditions, Journal of Engineering for Gas Turbines and Power, Vol. 133, pp.012902-1-7, (2011).
L. Fingjun, Y. Lin, X. Li, Numerical simulation for carbon steel flow-induced corrosion in high-velocity flow seawater, Journal of Anti-Corrosion Methods and Materials, Vol. 55/2, pp.66-72, (2008).
J. M. Pietralik, K. L. Heppner, Flow-accelerated corrosion susceptibility prediction of recirculating steam generator internals, Proceedings of the 16th International Conference on Nuclear Engineering, ICONE16, May 11-15, Orlando, Florida, USA, ICONE16-48630, (2008).
J.W. Kim, M.G. Na, C.Y. Park, Effect of local wall thinning on the collapse behavior of pipe elbows subjected to a combined internal pressure and in-plane bending load, Journal of Nuclear Engineering and design Vol. 238, pp.1275-1285, (2008).
B. Bozzini, M.E. Ricitti, M. Boniardi, C. Mele, Evaluation of erosion-corosion in multiphase flow via CFD and experimental analysis, Wear, Vol. 255, pp.237-245, (2003).
E.W. Adams, J.P. Johnston, Effects of the separating shear layer on the reattachment flow structure Part 2: Reattachment length and wall shear stress, Experiments in Fluids Vol.6, pp. 493-499, (1988).
M. Founti, Th. Achimastos, D. Dimopoulos, Effects of increasing particle loading in an axisymmetric vertical liquid-solid sudden expansion flow, in: Experimental and Computational Aspects of Validation of Multiphase Flow CFD Codes, ASME Fluid Engineering Division, Vol. 180, pp. 83-92, (1994).
H.K Versteeg and W. Malalasekera, An Introduction to computational fluid dynamics the finite volume method (Longman, 1995).
ANSYS Fluent® version 12.1 Users Guide (2009).
R. Debnath, B. Somnath, M. Arindam, D. Roy, M. Snehamoy, A comparative study with flow visualization of turbulent fluid flow in an elbow, International Journal of Engineering Science and Technology, Vol. 2(9), pp.4108-4121, (2010).
S.C. Jana, G. Matacalfe, J.M. Ottino, Experimental and computational studies of mixing in complex stokes flows: the vortex mixing flow and multicellular cavity flows. Journal Fluid Mechanics, Vol. 269, pp.199-246, (1994).
P.G. Drazin, W.H. Reid, Hydrodynamic Stability (Cambridge University Press, 1981).
T. MA, S. Wang, Structure of 2D incompressible flows with the Dirichlet boundary conditions, Discrete Continuum Dynamical Systems B, Vol.1, pp.29- 41, (2001).
M. Founti, A. Klipfel, Experimental and computational investigations of nearly dense two-phase sudden expansion flows, Experimental Thermal and fluid Science, Vol.17, pp.27-36, (1998).
R.V. Westphal, J.P. Johnston, J.K. Eaton, Experimental study of flow reattachment in a single-sided sudden expansion, NASA CR-3765, (1988).
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