An experimental investigation was performed to investigate two-dimensional axial velocity field at downstream of the 90 ° double bend pipe with and without inlet swirling condition. The main objectives are to find separation region and observe the influence of inlet swirling flow on the velocity fluctuation using ultrasound technique. The experiments were carried out in the pipe at Reynolds number Re = 1 × 10 4 . In case of inlet swirling flow condition, a rotary swirler was used as swirling generator, and the swirl number was setup S = 1. The ultrasonic measurements were taken at four downstream locations of the second bend pipe. Phased Array Ultrasonic Velocity Profiler (Phased Array UVP) technique was applied to obtain the two-dimensional velocity of the fluid and the axial and tangential velocity fluctuation. It was found that the secondary reverse flow became smaller at the downstream from the bend when the inlet condition on the first bend was swirling flow. In addition, inlet swirling condition influenced mainly on the tangential velocity fluctuation, and its maximum turbulence intensity was 40%.
Sudo, K., Sumida, M. and Hibara, H. (1998) Experimental Investigation on Turbulent Flow in a Circular-Sectioned 90-Degree Bend. Experiments in Fluids, 25, 42-49. https://doi.org/10.1007/s003480050206
Paidoussis, M.P. (1983) A Review of Flow-Induced Vibrations in Reactors and Reactor Components. Nuclear Engineering and Design, 74, 31-60. https://doi.org/10.1016/0029-5493(83)90138-3
Enayet, M.M., Gibson, M.M., Taylor, A.M.K.P. and Yianneskis, M. (1982) Laser-Doppler Measurements of Laminar and Turbulent Flow in a Pipe Bend. International Journal of Heat and Fluid Flow, 3, 213-219. https://doi.org/10.1016/0142-727X(82)90024-8
Crawford, N., Spence, S., Simpson, A. and Cunningham, G. (2009) A Numerical Investigation of the Flow Structures and Losses for Turbulent Flow in 90 Elbow Bends. Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering, 223, 27-44. https://doi.org/10.1243/09544089JPME206
Dutta, P., Saha, S.K., Nandi, N. and Pal, N. (2016) Numerical Study on Flow Separation in 90 Pipe Bend under High Reynolds Number by k-ε Modelling. Engineering Science and Technology, an International Journal, 19, 904-910. https://doi.org/10.1016/j.jestch.2015.12.005
Röhrig, R., Jakirlic, S. and Tropea, C. (2015) Comparative Computational Study of Turbulent Flow in a 90 Pipe Elbow. International Journal of Heat and Fluid Flow, 55, 120-131. https://doi.org/10.1016/j.ijheatfluidflow.2015.07.011
Kim, J., Yadav, M. and Kim, S. (2014) Characteristics of Secondary Flow Induced by 90-Degree Elbow in Turbulent Pipe Flow. Engineering Applications of Computational Fluid Mechanics, 8, 229-239. https://doi.org/10.1080/19942060.2014.11015509
Kawamura, T., Nakao, T. and Takahashi, M. (2002) Reynolds Number Effect on Turbulence Downstream from Elbow Pipe. Transactions of the Japan Society of Mechanical Engineers Series B, 68, 645-651.
Ono, A., Kimura, N., Kamide, H. and Tobita, A. (2011) Influence of Elbow Curvature on Flow Structure at Elbow Outlet under High Reynolds Number Condition. Nuclear Engineering and Design, 241, 4409-4419. https://doi.org/10.1016/j.nucengdes.2010.09.026
Kubo, T., Ebara, S. and Hashizume, H. (2012) Experimental Study of Influence of Elbow Curvature on a Swirling Flow Generated in a Three-Dimensionally Connected Dual Elbow. E-Journal of Advanced Maintenance, 5, 34-41.
Sudo, K., Takami, T., Hibara, H., Nomura, T. and Sumida, M. (1997) Weakly Swirling Flows through a 90 Bend. Transactions of the Japan Society of Mechanical Engineers, Series B, 63, 505-512.
Kalpakli, A. and Örlü, R. (2013) Turbulent Pipe Flow Downstream a 90 Pipe Bend with and without Superimposed Swirl. International Journal of Heat and Fluid Flow, 41, 103-111. https://doi.org/10.1016/j.ijheatfluidflow.2013.01.003
Yamano, H., Tanaka, M., Murakami, T., Iwamoto, Y., Yuki, K., Sago, H. and 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, 48, 677-687. https://doi.org/10.1080/18811248.2011.9711749
Yamano, H., Tanaka, M.A., Kimura, N., Ohshima, H., Kamide, H. and Watanabe, O. (2011) Development of Flow-Induced Vibration Evaluation Methodology for Large-Diameter Piping with Elbow in Japan Sodium-Cooled Fast Reactor. Nuclear Engineering and Design, 241, 4464-4475. https://doi.org/10.1016/j.nucengdes.2011.06.005
Mizutani, J., Ebara, S. and Hashizume, H. (2016) Evaluation of the Influence of the Inlet Swirling Flow on the Flow Field in a Triple Elbow System. International Journal of Hydrogen Energy, 41, 7233-7238. https://doi.org/10.1016/j.ijhydene.2016.02.040
Ebara, S., Takamura, H., Hashizume, H. and Yamano, H. (2016) Characteristics of Flow Field and Pressure Fluctuation in Complex Turbulent Flow in the Third Elbow of a Triple Elbow Piping with Small Curvature Radius in Three-Dimensional Layout. International Journal of Hydrogen Energy, 41, 7139-7145. https://doi.org/10.1016/j.ijhydene.2016.02.068
Takeda, Y. (1986) Velocity Profile Measurement by Ultrasound Doppler Shift Method. International Journal of Heat and Fluid Flow, 7, 313-318. https://doi.org/10.1016/0142-727X(86)90011-1
Takeda, Y. and Kikura, H. (2002) Flow Mapping of the Mercury Flow. Experiments in Fluids, 32, 161-169. https://doi.org/10.1007/s003480100296
Fukumoto, T., Tsukada, K., Ihara, T., Tsuzuki, N. and Kikura, H. (2013) A Study of Phased Array Ultrasonic Velocity Profile Monitor for Flow Rate Measurement. Proceedings of 21st International Conference on Nuclear Engineering, Chengdu, 29 July-2 August 2013, Paper No. ICONE21-16601, 1-6. https://doi.org/10.1115/ICONE21-16601
Ocheltree, K.B. and Frizzel, L.A. (1989) Sound Field Calculation for Rectangular Sources. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 36, 242-248. https://doi.org/10.1109/58.19157
Hamdani, A., Ihara, T. and Kikura, H. (2016) Experimental and Numerical Visualizations of Swirling Flow in a Vertical Pipe. Journal of Visualization, 19, 369-382. https://doi.org/10.1007/s12650-015-0340-8
Saraç, B.A. and Bali, T. (2007) An Experimental Study on Heat Transfer and Pressure Drop Characteristics of Decaying Swirl Flow through a Circular Pipe with a Vortex Generator. Experimental Thermal and Fluid Science, 32, 158-165. https://doi.org/10.1016/j.expthermflusci.2007.03.002
Takano, T., Ikarashi, Y., Uchiyama, K., Yamagata, T. and Fujisawa, N. (2016) Influence of Swirling Flow on Mass and Momentum Transfer Downstream of a Pipe with Elbow and Orifice. International Journal of Heat and Mass Transfer, 92, 394-402. https://doi.org/10.1016/j.ijheatmasstransfer.2015.08.087
Rocklage-Marliani, G., Schmidts, M. and Ram, V.I.V. (2003) Three-Dimensional Laser-Doppler Velocimeter Measurements in Swirling Turbulent Pipe Flow. Flow, Turbulence and Combustion, 70, 43-67. https://doi.org/10.1023/B:APPL.0000004913.82057.81
Kitoh, O. (1991) Experimental Study of Turbulent Swirling Flow in a Straight Pipe. Journal of Fluid Mechanics, 225, 445-479. https://doi.org/10.1017/S0022112091002124
Pashtrapanska, M., Jovanovic, J., Lienhart, H. and Durst, F. (2006) Turbulence Measurements in a Swirling Pipe Flow. Experiments in Fluids, 41, 813-827. https://doi.org/10.1007/s00348-006-0206-x