Vol 8, No 4 (2017) > Mechanical Engineering >

Numerical Study about the Change in Flow Separation and Velocity Distribution in a 90o Pipe Bend with/without Guide Vane Conditions

Sumit Kumar Saha, Nityananda Nandi

 

Abstract: A single phase, incompressible turbulent flow through a 90º pipe bend with/without guide vane conditions has been studied here. The present work deals with the numerical simulation to investigate the change in flow separation and velocity distribution at the downstream section due to the effect of the guide vane. The k-ε turbulence model has been adopted for simulation purposes to obtain the results. After the validation of existing experimental and numerical results, a detailed study has been performed for three different Reynolds number and four different positions of the guide vane. The value of the Curvature ratio (Rc/D) has been considered as one factor for the present study. The curvature ratio can be defined as the ratio between the bend curvature radius and hydraulic diameter of the pipe. The results obtained from the present study have been presented in graphical form. A flow separation region has been found at the bend outlet for flow through 90º pipe bend without the guide vane. This flow separation region was absent for the cases which dealt with the flow through 90º pipe bend with the guide vane. Velocity distribution at four different downstream positions for different cases and different Reynolds numbers have been compared and reported in the present study.
Keywords: 90º pipe bend; Flow separation; Numerical study; Velocity distribution; With/without guide vane

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References


Anwer, M., So, R.M., Lai, Y.G., 1989. Perturbation by and Recovery from Bend Curvature of a Fully Developed Turbulent Pipe Flow. Physics of Fluids A: Fluid Dynamics, Volume 1(8), pp.1387−1397

Boersma, B.J., Nieuwstadt, F.T., 1996. Large-eddy Simulation of Turbulent Flow in a Curved Pipe. Journal of Fluids Engineering, Volume 118, pp. 248−254

Chang, T.-H., 2003. An Investigation of Heat Transfer Characteristics of Swirling Flow in a 180° Circular Section Bend with Uniform Heat Flux. KSME International Journal, Volume 17, pp. 1520−1532

Dean, W.R., Hurst, J.M., 1959. Note on the Motion of Fluid in a Curved Pipe. Mathematika, Volume 6, pp. 77−85

Dutta, P., Nandi, N., 2015. Effect of Reynolds Number and Curvature Ratio on Single Phase Turbulent Flow in Pipe Bends. Mechanics and Mechanical Engineering, Volume 19, pp. 5−16

Feng, B., Wang, S., Li, S., Yang, X., Jiang, S., 2014. Experimental and Numerical Study on Pressure Distribution of 90º Elbow for Flow Measurement. Science and Technology of Nuclear Installations, Volume 2014, pp. 1−7

Goodarzi, M., Safaei, M.R., Vafai, K., Ahmadi, G., Dahari, M., Kazi, S.N., Jomhari, N., 2014. Investigation of Nanofluid Mixed Convection in a Shallow Cavity using a Two-phase Mixture Model. International Journal of Thermal Sciences, Volume 75, pp. 204−220

Hellström, F., 2010. Numerical Computations of the Unsteady Flow in Turbochargers.

Homicz, G.F., 2004. Computational Fluid Dynamic Simulations of Pipe Elbow Flow. United States, Department of Energy

Hüttl, T.J., Friedrich, R., 2001. Direct Numerical Simulation of Turbulent Flows in Curved and Helically Coiled Pipes. Computers & Fluids, Volume 30, pp. 591−605

Imao, S., Itoh, M., Harada, T., 1996. Turbulent Characteristics of the Flow in an Axially Rotating Pipe. International Journal of Heat and Fluid Flow, Volume 17, pp. 444−451

Keulegan, G.H., Beij, K.H., 1937. Pressure Losses for Fluid Flow in Curved Pipes. US Government Printing Office

Kim, J., Yadav, M., Kim, S., 2014. Characteristics of Secondary Flow Induced by 90-degree Elbow in Turbulent Pipe Flow. Engineering Applications of Computational Fluid Mechanics, Volume 8, pp. 229−239

Ono, A., Kimura, N., Kamide, H., Tobita, A., 2011. Influence of Elbow Curvature on Flow Structure at Elbow Outlet under High Reynolds Number Condition. Nuclear Engineering and Design, Volume 241, pp. 4409−4419

Pittard, M.T., Blotter, J.D., 2003. Numerical Modeling of LES based Turbulent Flow Induced Vibration. ASME 2003 International Mechanical Engineering Congress and Exposition, pp. 141−148

Qing, M., Jinghui, Z., Yushan, L., Haijun, W., Quan, D., 2006. Experimental Studies of Orifice-induced Wall Pressure Fluctuations and Pipe Vibration. International Journal of Pressure Vessels and Piping, Volume 83, pp. 505−511

Rahimzadeh, H., Maghsoodi, R., Sarkardeh, H., Tavakkol, S., 2012. Simulating Flow Over Circular Spillways by using Different Turbulence Models. Engineering Applications of Computational Fluid Mechanics, Volume 6, pp. 100−109

Rütten, F., Schröder, W., Meinke, M., 2005. Large-eddy Simulation of Low Frequency Oscillations of the Dean Vortices in Turbulent Pipe Bend Flows. Physics of Fluids, Volume 17(3)

Safaei, M.R., Goshayeshi, H.R., Razavi, B.S., Goodarzi, M., 2011. Numerical Investigation of Laminar and Turbulent Mixed Convection in a Shallow Water-filled Enclosure by Various Turbulence Methods. Scientific Research and Essays, Volume 6, pp. 4826−4838

So, R.M.C, Anwer, M., 1993. Swirling Turbulent Flow through a Curved Pipe. Experiments in Fluids, Volume 14(3), pp. 169−177

Tu, J., Yeoh, G.H., Liu, C., 2007. Computational Fluid Dynamics: A Practical Approach. Butterworth-Heinemann, an imprint of Elsevier, Waltham, Massachusetts, USA and Oxford, United Kingdom

White, A., 1964. Flow of a Fluid in an Axially Rotating Pipe. Journal of Mechanical Engineering Science, Volume 6, pp. 47−52

Yamano, H., Tanaka, M., Murakami, T., Iwamoto, Y., Yuki, K., Sago, H., Hayakawa, S., 2011. Unsteady Elbow Pipe Flow to Develop a Flow-induced Vibration Evaluation Methodology for Japan Sodium-cooled Fast Reactor. Journal of Nuclear Science and Technology, Volume 48, pp. 677−687

Zhang, H., Zhang, X., Sun, H., Chen, M., Lu, X., Wang, Y., Liu, X., 2013. Pressure of Newtonian Fluid Flow through Curved Pipes and Elbows. Journal of Thermal Science, Volume 22, pp. 372−376

Zhang, T., Zhang, Y.O., Ouyang, H., 2015. 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, Volume 125, pp. 66−77