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Numerical Study of Flow Characteristics over Square Cylinders with an Attached Splitter Plate

  • Nguyen, Van Minh (Department of Eco-friendly Offshore Plant FEED Engineering, Changwon National University) ;
  • Koo, Bon-Guk (Department of Naval Architecture and Marine Engineering, Changwon National University)
  • Received : 2018.04.04
  • Accepted : 2018.06.10
  • Published : 2018.06.30

Abstract

The fluid flow over structures has been widely investigated by many researchers because its extensive application in offshore structures, skyscrapers, chimneys and cooling towers, brides. In the viewpoint of reducing the drag for offshore structure, it becomes challenging problem in the field of hydrodynamic of offshore structure. The purpose of this study is to investigate a flow over a square cylinder with an attached splitter plate using RANS method. First, RANS turbulent models such as a standard $k-{\omega}$ model, SST $k-{\omega}$ model, RNG $k-{\varepsilon}$ model, realizable $k-{\varepsilon}$ model, standard $k-{\varepsilon}$ model were used for choosing suitable turbulent model which has the best agreement with available experimental result. Drag of single cylinder estimated by using standard $k-{\omega}$ has a good agreement with published experimental result. Therefore, the stand $k-{\omega}$ was selected for simulation for flow over a square cylinder with an attached plate. Second, the numerical results of drag of square cylinder with an attached splitter plate in various length of an attached plate were performed using RANS method in ANSYS Fluent. In this paper, the numerical simulations were conducted at a Reynolds number of 485 and the thickness of the splitter plate is chosen as a constant value about 10% of cylinder width. The numerical results of drag coefficient of square cylinder are compared with experimental result published by other researchers. Finally, the effect of the splitter plate attached to the rear side of the square cylinder has been investigated numerically with a focus on the drag coefficient and flow characteristic. As a result, the drag coefficient decreases with an increase in splitter plate length.

Keywords

References

  1. Bai W., Mingham, C.G., Causon, D.M., Qian L. (2016). Detached eddy simulation of turbulent flow around square and cylinders on Cartesian cut cells, Ocean Engineering, pp 1-14.
  2. Chauhan, M. K., Dutta, S., More, B.S. and Gandhi, K. (2017). Experimental investigation of flow over a square cylinder with an attached splitter plate at intermediate Reynolds number, Journal of Fluids and Structures, pp 319-335.
  3. Dey P. and Das, A.K. (2015). Steady flow over triangular extended solid attached to square cylinder - A method to reduce drag, Ain Shams Engineering Journal, pp 929-938.
  4. Dey P. and Das, A.K. (2015). Numerical analysis of drag and lift reduction of square cylinder, Engineering Science and Technology and International Journal, pp 758 - 768.
  5. Kim, D.H., Yang, K.S. and Senda, M. (2004). Large eddy simulation of turbulent flow past a square cylinder confined in a channel, Computer and Fluids, pp 81-96.
  6. Kumar S.R., Sharma, A. and Agrawal A. (2008). Simulation of flow around a row of square cylinders, Journal Fluid Mech., pp 368-397.
  7. Lubcke, H., Schmidt, S., Rung, T. and Thiele, F. (2011). Comparison of LES and RANS in bluff-body flows, J Wind. Eng. Ind. Aerody, pp 1471-1485.
  8. Lyn, D.A., Einav, S., Rodi, W. and Park, J.H. (1995). A laser-Doppler velocimetry study of ensembleaveraged characteristics of the turbulent near wake of a square cylinder, Journal Fluid Mech., pp 285-319.
  9. Paul, A.R., Joshi, S., Jindal, A., Maurya, S.P, Tiwari, P.K and Jain A. (2013). Effects of upstream Rod's shape on drag of a square cylinder, Proceeding of 3rd International Conference on Mechanical, Automotive and Materials Engineering (ICMAME 2013), pp 35-40.
  10. Schewe G. (2013). Reynolds-number-effects in flow around a rectangular cylinder with aspect ratio 1:5, Journal of Fluids and Structures, pp. 15-26.
  11. Trias, F.X., Gorobets, A. and Oliva, A. (2015). Turbulent flow around a square cylinder at Reynold number 22,00: DNS study, Computer and Fluids, pp 87-98.
  12. Xu, F., Ying, X. and Zhang Z. (2011). Prediction of unsteady flow around a square cylinder using RANS, Applied Mechanics and Material, pp 1165-1170.
  13. FLUENT, Inc., ANSYS FLUENT 12.0 Theory guide. (2019).