Study on swirl flow in a draft tube of a bulb hydro turbine model
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초록
The present study focuses on the effect of swirl flow in a draft tube on the performance of a bulb hydro turbine model at various turbine operating conditions by CFD analysis. First, the performance characteristics of the bulb turbine model were investigated. Subsequently, four operating conditions were chosen for loss analysis in the downstream region of the turbine model. Next, the swirl number was calculated along the downstream region at different turbine operating conditions. Moreover, the internal flow was examined to understand the turbine performance characteristics. From this study, it was observed that the swirl number was proportional to the loss in the downstream region of the turbine model. For the high swirl number, i.e., PL1 and PL2 conditions, the internal flow investigation indicated a relatively large recirculation region in the downstream region. For the low swirl number, i.e., BEP condition, a smooth streamline was found. Thus, the high efficiency of the turbine model is illustrated in this condition.
Abstract
The present study focuses on the effect of swirl flow in a draft tube on the performance of a bulb hydro turbine model at various turbine operating conditions by CFD analysis. First, the performance characteristics of the bulb turbine model were investigated. Subsequently, four operating conditions were chosen for loss analysis in the downstream region of the turbine model. Next, the swirl number was calculated along the downstream region at different turbine operating conditions. Moreover, the internal flow was examined to understand the turbine performance characteristics. From this study, it was observed that the swirl number was proportional to the loss in the downstream region of the turbine model. For the high swirl number, i.e., PL1 and PL2 conditions, the internal flow investigation indicated a relatively large recirculation region in the downstream region. For the low swirl number, i.e., BEP condition, a smooth streamline was found. Thus, the high efficiency of the turbine model is illustrated in this condition.
참고문헌 (19)
- P. Dörfler, "Flow-Induced Pulsation and Vibration in Hydroeletric Machinery Zurich" (2012), Springer Verlag London
- S. W. Armfield, "Numerical simulation of swirling flow in diffusers", International Journal For Numerical Methods in Fluid, 6(8), pp.541~556 (1986)
- Y. Senoo, "Swirl flow in conical diffusers", Bulletin of the JSME, 21(151), pp.112~119 (1978)
- R. P. Lohmann, "Swirling flow through annular diffusers with conical walls", Journal of Fluids Engineering, 101(2), pp.224~229 (1979)
- Michihiro Nishi, "An Outlook on the Draft-Tube-Surge Study", International Journal of Fluid Machinery and Systems, 6(1), pp.33~48 (2013), 한국유체기계학회[DOI]
- E. T. V. Daurico, "Numerical analysis of swirl effects on conical diffuser flows", Journal of Aerospace Technology and Management, 9(1), pp.91~100 (2017)
- Zhenmu Chen, "Suppression of unsteady swirl flow in the draft tube of a Francis hydro turbine model using J-Groove", Journal of Mechanical Science and Technology, 31(12), pp.5813~5820 (2017), 대한기계학회
- Z. D. Quian, "Numerical simulation and analysis of pressure pulsation in Francis hydraulic turbine with air admission", Journal of Hydrodynamic, 19(4), pp.467~472 (2007)
- M. Nishi, "An experimental study on fins, their role in control of the draft tube surging", Hydraulic Machinery and Cavitation, pp.905~914 (1996)
- A. L. Bosioc, "Unsteady pressure analysis of a swirling flow with vortex rope and axial water injection in a discharge cone", Journal of Fluids Engineeing, 134(8), pp.0811041~08110411 (2012)
- Y D. Choi, "Suppression of cavitation in inducers by J-Groove", Journal of Fluid Engineering, 129(1), pp.15~22 (2007)
- J. Kurokawa, "Effect of J-Groove on the suppression of swirl flow in a conical diffuser", Journal of Fluids Engineering, 132(7), pp.071101~071108 (2010)
- J. Kurokawa, "J-Groove technique for suppressing various anomalous flow phenomenon in turbomachines", Internaltional Journal of Fluid Machinery and Systems, 4(1), pp.1~13 (2011)
- S. L. Saha, "Suppression of performance curve instability of a mixed flow pump by use of J-Groove", Journal of Fluids Engineering, 122(3), pp.592~597 (2000)
- "ANSYS CFX Documentation, ver. 18.1"[URL]
- D. Jost, "Numerical prediction of efficiency, cavitation and unsteady phenomena in water turbines", roceedings of the 9th Biennial ASME conference on engineering systems design and analysis, pp.157~166 (2008)
- R. Menter, "Two-equation Eddy-Viscosity turbulence models for engineering applications", AIAA Journal, 32(8), pp.1598~1605 (1994)
- T. H. Shih, "A new k-εEddy viscosity model for high Reynolds number turbulent flows", Computers and Fluids, 24(3), pp.227~238 (1995)
- S. Muntean, "Mathematical, numerical and experimental analysis of the swirling flow at a Kaplan runner outlet", IOP Conference Series: Earth and Environmental Science, 15(3), pp.032001~ (2012)