The Effect of the Pipe Bending Angle on the Pressure Losses Vane Elbow PipesAuthor : SamanShabani, Amir Abass Abedini and Ali Mohammadtabar
Volume 8 No.1 January-June 2019 pp 1-8
Pressure loss is one of the significant parameters in designing pipe bends. In this paper, the pressure distribution and pressure losses induced by turbulent ﬂows in a circular cross-sectioned piping elbow with or without guide vane were simulated. The flow distribution in the piping elbow was simulated by the k- model using control volume method. The main objective of this study is to characterize the effect of changing the angle of pipe bend and Reynolds number on the flow separation of single-phase turbulent flow through numerical simulation. Results were validated by other experimental results and then loss coefficient was calculated in different angles from 45 to 135-degree pipe bend in various radius ratios with or without guide vane. Despite the fact that increasing pipe angle increased the pipe bend loss coefficient, using guide vane in the pipe elbow decreased this coefficient. In the radius ratio 1.5 with one guide vane, the loss coefficient of the pipe bends decreased by 50 percent in all degrees. Results revealed that the use of two vanes in pipe bend is more effective on the reduction of elbow pressure losses. Moreover, two guide vanes can decrease loss coefficient more than 50 percent. Also, the results indicated that loss coefficient decreased by increasing Reynolds number.
Turbulence Flow, Drop Pressure, Pipe Bend, Guide Vane
 T.K.Bandyopadhyay, and S.K. Das, “Non-Newtonian and Gas-non-Newtonian Liquid Flow through Elbows-CFD Analysis”, Journal of Applied Fluid Mechanics, Vol. 6, No. 1, pp. 131–14, 2013.
 K.H. Beij, “Pressure losses for fluid flow in 90 degree pipe bends” Journal of Research of the National Bureau of Standards, Vol. 21, No. 1, pp. 1, 1938, DOI: 10.6028/jres.021.001.
 N.M.Crawford, G.Cunningham, and S.W.T. Spence, “An experimental investigation into the pressure drop for turbulent flow in 90° elbow bends” Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering, Vol. 221, No. 2, pp. 77–88, 2007, DOI: 10.1243/0954408JPME84.
 R. Debnath, A.Mandal, S.Majumder, S.Bhattacharjee, and D.Roy, “Numerical Analysis of Turbulent Fluid Flow and Heat Transfer in a Rectangular Elbow” Vol. 8, No. 2, pp. 231–241, 2015.
 P.,Dutta, and N.Nandi, “Study on Pressure Drop Characteristics of Single Phase Turbulent Flow in Pipe Bend for High Reynolds Number” Vol. 10, No. 5, pp. 2221–2226, 2015.
 P.Dutta, S.K.Saha, N.Nandi, and N.Pal, “Numerical study on flow separation in 90° pipe bend under high Reynolds number by k-ε modelling” Engineering Science and Technology, an International Journal, Vol. 19, No. 2, pp. 904–910, 2016 DOI: 10.1016/j.jestch. 2015.12.005.
 J.T.Haskew, and M. a. R.Sharif, “Performance evaluation of vaned pipe bends in turbulent flow of liquid propellants” Applied Mathematical Modelling, Vol. 21, No. 1, pp. 48–62, 1997 DOI: 10.1016/S0307-904X(96)00121-7.
 G.F.Homicz, “Computational Fluid Dynamic Simulations of Pipe Elbow Flow” No. August, p. SAND2004-3467, 2004 DOI: SAND 2004-3467.
 H.Itō, “Pressure Losses in Smooth Pipe Bends” Journal of Basic Engineering, Vol. 82, No. 1, pp. 131, 1960 DOI: 10.1115/1.3662501.
 H.Ito, T.Procedure, and E.Results, “ Pressure Losses in Varied Elbows of a Circular Cross Section An Influence of Superheat Upon the Spray Configurations of Superheated Liquid Jets 1” No. september 1966, pp. 5–6, 2015.
 J.Kim, M.Yadav, and S.Kim, “Characteristics of secondary flow induced by 90-degree elbow in turbulent pipe flow” Engineering Applications of Computational Fluid Mechanics, Vol. 8, No. 2, pp. 229–239, 2014, DOI: 10.1080/19942060.2014.11015509.
 G.H.Lee, Y.D.Choi, and S.H.Han, “Measurement of developing turbulent flow in a U-bend of circular cross-section” Journal of mechanical science and technology, Vol. 21, No. 2, pp. 348–359, 2007.
 J.Liu, T.Zhang, and Y.Zhang, “Numerical study on flow-induced noise for a steam stop-valve using large eddy simulation” Journal of Marine Science and Application, Vol. 12, No. 3, pp. 351–360, 2013 DOI: 10.1007/s11804-013-1195-9.
 P.P.Modi, and S.Jayanti, “Pressure Losses and Flow Maldistribution in Ducts with Sharp Bends” Chemical Engineering Research and Design, Vol. 82, No. 3, pp. 321–331, 2004, DOI: 10.1205/026387604322870435.
 S.F.Moujaes, and S.Aekula, CFD, “Predictions and Experimental Comparisons of Pressure Drop Effects of Turning Vanes in 90° Duct Elbows” Journal of Energy Engineering, Vol. 135, No. 4, pp. 119–126, 2009. DOI: 10.1061/(ASCE)0733-9402(2009)135:4(119).
 B.B.Nayak, D.Chatterjee, and A.N.Mullick, “Numerical prediction of flow and heat transfer characteristics of water-fly ash slurry in a 180?? return pipe bend” International Journal of Thermal Sciences, Vol. 113, pp. 100–115, 2017 DOI: 10.1016/j.ijthermalsci.2016.11. 019.
 R Röhrig S Jakirlić and C Tropea “Comparative computational study of turbulent flow in a 90° pipe elbow” International Journal of Heat and Fluid Flow, Vol. 55, pp. 120–131, 2015 DOI: 10.1016/ j.ijheatfluidflow.2015.07.011.
 C.Rumsey, and T.Beutner, 2006. Introduction: Computational Fluid Dynamics Validation for Synthetic Jets.
 K.Sudo, M.Sumida, and H.Hibara, “Experimental investigation on turbulent flow in a circular-sectioned 180-degree bend” Experiments in Fluids, Vol. 28, No. 1, pp. 51–57, 2000 DOI: 10.1007/s003480050 206.
 M.Tanaka, and H.Ohshima, “Numerical Investigation on Large Scale Eddy Structure in Unsteady Pipe Elbow Flow at High Reynolds Number Conditions with Large Eddy Simulation Approach” Journal of Power and Energy Systems, Vol. 6, No. 2, pp. 210–228, 2012 DOI: 10.1299/jpes.6.210.
 L.Wang, D.Gao, and Y.Zhang, “Numerical simulation of turbulent flow of hydraulic oil through 90° circular-sectional bend” Chinese Journal of Mechanical Engineering, Vol. 25, No. 5, pp. 905–910, 2012 DOI: 10.3901/CJME.2012.05.905.
 M. V.Zagarola and A.J.Smits, “Mean-flow scaling of turbulent pipe flow” Journal of Fluid Mechanics, Vol. 373, p. S0022112098 002419, 1998 DOI: 10.1017/S0022112098002419.
 T.Zhang, Y.O.Zhang, and H.Ouyang, “Structural vibration and fluid-borne noise induced by turbulent flow through a 90° piping elbow with/without a guide vane” International Journal of Pressure Vessels and Piping, Vol. 125, pp. 66–77, 2015 DOI: 10.1016/j.ijpvp.2014. 09.004.
 T.Zhang, Y.Zhang, H.Ouyang, and T.Guo, “Flow-induced noise and vibration analysis of a piping elbow with/without a guide vane” Journal of Marine Science and Application, Vol. 13, No. 4, pp. 394–401, 2014 DOI: 10.1007/s11804-014-1271-9.
 H.Zhang, X.Zhang, H.Sun, M.Chen, X.Lu, Y.Wang, and X.Liu, “Pressure of Newtonian fluid flow through curved pipes and elbows” Journal of Thermal Science, Vol. 22, No. 4, pp. 372–376, 2013 DOI: 10.1007/s11630-013-0638-6.