Wind and Structures

Techno-Press (테크노프레스)
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Experimental study on Re number effects on aerodynamic characteristics of 2D square prisms with corner modifications

  • Wang, Xinrong (State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University) ;
  • Gu, Ming (State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University)
  • Received : 2015.06.04
  • Accepted : 2016.04.11
  • Published : 2016.05.25
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Abstract

Simultaneous pressure measurements on 2D square prisms with various corner modifications were performed in uniform flow with low turbulence level, and the testing Reynolds numbers varied from $1.0{\times}10^5$ to $4.8{\times}10^5$. Experimental models were a square prism, three chamfered-corner square prisms (B/D=5%, 10%, and 15%, where B is the chamfered corner dimension and D is the cross-sectional dimension), and six rounded-corner square prisms (R/D =5%, 10%, 15%, 20%, 30%, and 40%, where R is the corner radius). Experimental results of drag coefficients, wind pressure distributions, power spectra of aerodynamic force coefficients, and Strouhal numbers are presented. Ten models are divided into various categories according to the variations of mean drag coefficients with Reynolds number. The mean drag coefficients of models with $B/D{\leq}15%$ and $R/D{\leq}15%$ are unaffected by the Reynolds number. On the contrary, the mean drag coefficients of models with R/D=20%, 30%, and 40% are obviously dependent on Reynolds number. Wind pressure distributions around each model are analyzed according to the categorized results.The influence mechanisms of corner modifications on the aerodynamic characteristics of the square prism are revealed from the perspective of flow around the model, which can be obtained by analyzing the local pressures acting on the model surface.

Keywords

Acknowledgement

Supported by : National Natural Science Foundation of China

References

  1. Bearman, P.W. and Obasaju, E.D. (1982), "An experimental study of pressure fluctuations on fixed and oscillating square-section cylinders", J. Fluid Mech., 119, 297-321. https://doi.org/10.1017/S0022112082001360
  2. Bosch, G. and Rodi, W. (1998), "Simulation of vortex shedding past a square cylinder with different turbulence models", Int. J. Numer. Meth. Fl., 28(4), 601-616. https://doi.org/10.1002/(SICI)1097-0363(19980930)28:4<601::AID-FLD732>3.0.CO;2-F
  3. Cao, S., Zhou, Q. and Zhou, Z. (2014), "Velocity shear flow over rectangular cylinders with different side ratios", Comput. Fluids., 96, 35-46. https://doi.org/10.1016/j.compfluid.2014.03.002
  4. Carassale, L., Freda, A. and Marre-Brunenghi, M. (2013), "Effects of free-stream turbulence and corner shape on the galloping instability of square cylinders", J. Wind Eng. Ind. Aerod., 123, 274-280. https://doi.org/10.1016/j.jweia.2013.09.002
  5. Carassale, L., Freda, A. and Marre-Brunenghi, M. (2014), "Experimental investigation on the aerodynamic behavior of square cylinders with rounded corners", J. Fluid. Struct., 44, 195-204. https://doi.org/10.1016/j.jfluidstructs.2013.10.010
  6. Choi, C.K. and Kwon, D.K. (2003), "Effects of corner cuts and angles of attack on the Strouhal number of rectangular cylinders", Wind Struct., 6(2), 127-140. https://doi.org/10.12989/was.2003.6.2.127
  7. Gu, M. and Quan, Y. (2004), "Across-wind loads of typical tall buildings", J. Wind Eng. Ind. Aerod., 92(13), 1147-1165. https://doi.org/10.1016/j.jweia.2004.06.004
  8. Hayashida, H. and Iwasa, Y. (1990), "Aerodynamic shape effects of tall building for vortex induced Vibration", J. Wind Eng. Ind. Aerod., 33(1), 237-242. https://doi.org/10.1016/0167-6105(90)90039-F
  9. Huang, R.F., Lin, B.H. and Yen, S.C. (2010), "Time-averaged topological flow patterns and their influence on vortex shedding of a square cylinder in crossflow at incidence", J. Fluid. Struct., 26(3), 406-429. https://doi.org/10.1016/j.jfluidstructs.2010.01.003
  10. Huang, R.F. and Lin, B.H. (2011), "Effects of flow patterns on aerodynamic forces of a square cylinder at incidence", J. Mech., 27(3), 347-355. https://doi.org/10.1017/jmech.2011.37
  11. Igarashi, T. (1984), "Characteristics of the flow around a square prism", Bull. JSME, 27(231), 1858-1865. https://doi.org/10.1299/jsme1958.27.1858
  12. Knisely, C.W. (1990), "Strouhal numbers of rectangular cylinders at incidence: a review and new data", J. Fluid. Struct., 4(4), 371-393. https://doi.org/10.1016/0889-9746(90)90137-T
  13. Koutmos, P. and Mavridis, C. (1997), "A computational investigation of unsteady separated flows", Int. J. Heat Fluid Fl, 18(3), 297-306. https://doi.org/10.1016/S0142-727X(97)00009-X
  14. Kwok, K.C.S. (1988), "Effect of building shape on wind-induced response of tall building", J. Wind Eng. Ind. Aerod., 28(1), 381-390. https://doi.org/10.1016/0167-6105(88)90134-1
  15. Lee, B.E. (1975), "The effect of turbulence on the surface pressure field of a square prism", J. Fluid Mech., 69(2), 263-282. https://doi.org/10.1017/S0022112075001437
  16. Liang, S.G., Liu, S.C., Li, Q.S., Zhang, L.L. and Gu, M. (2002), "Mathematical model of across wind dynamic loads on rectangular tall buildings", J. Wind Eng. Ind. Aerod., 90(12), 1757-1770. https://doi.org/10.1016/S0167-6105(02)00285-4
  17. Lyn, D.A., Einav, S., Rodi, W. and Park, J.H. (1995), "A laser-Doppler velocimetry study of ensemble-averaged characteristics of the turbulent near wake of a square cylinder", J. Fluid Mech., 304, 285-319. https://doi.org/10.1017/S0022112095004435
  18. Miyashita, K., Katagiri, J., Nakamura, O., Ohkuma, T., Tamura, Y., Itoh, M. and Mimachi, T. (1993), "Wind-induced response of high-rise buildings Effects of corner cuts or openings in square buildings", J. Wind Eng. Ind. Aerod., 50, 319-328. https://doi.org/10.1016/0167-6105(93)90087-5
  19. Murakami, S. and Mochida, A. (1995), "On turbulent vortex shedding flow past 2D square cylinder predicted by CFD", J. Wind Eng. Ind. Aerod., 54, 191-211.
  20. Nakamura, Y. and Ohya, Y. (1984), "The effects of turbulence on the mean flow past two-dimensional rectangular cylinders", J. Fluid Mech., 149, 255-273. https://doi.org/10.1017/S0022112084002640
  21. Nakamura, Y. and Ozono, S. (1987), "The effects of turbulence on a separated and reattaching flow", J. Fluid Mech.,178, 477-490. https://doi.org/10.1017/S0022112087001320
  22. Naudascher, E., Weske, J.R. and Fey, B. (1981), "Exploratory study on damping of galloping vibrations", J. Wind Eng. Ind. Aerod., 8(1), 211-222. https://doi.org/10.1016/0167-6105(81)90020-9
  23. Nishimura, A. and Taniike, Y. (2000), "Fluctuating wind forces of a stationary two dim. square prism" (in Japanese), Proceedings of the 16th National Symposium on Wind Engineering, Tokyo, Japan.
  24. Norberg, C. (1993), "Flow around rectangular cylinders: pressure forces and wake frequencies", J. Wind Eng. Ind. Aerod., 49(1), 187-196. https://doi.org/10.1016/0167-6105(93)90014-F
  25. Okajima, A. (1982), "Strouhal numbers of rectangular cylinders", J. Fluid Mech., 123, 379-398. https://doi.org/10.1017/S0022112082003115
  26. Okajima, A. (1990), "Numerical simulation of flow around rectangular cylinders", J. Wind Eng. Ind. Aerod., 33(1), 171-180. https://doi.org/10.1016/0167-6105(90)90033-9
  27. Oka, S. and Ishihara, T. (2009), "Numerical study of aerodynamic characteristics of a square prism in a uniform flo", J. Wind Eng. Ind. Aerod., 97(11), 548-559. https://doi.org/10.1016/j.jweia.2009.08.006
  28. Ono, Y. and Tamura, T. (2001), "Numerical study for turbulent effect on aerodynamics of a square cylinder", Proceedings of the 5th Asia-Pacific Conference on Wind Engineering, Kyoto, Japan, October.
  29. Otsuki, Y., Fujii, K., Washizu, K.T. and Ohya, A. (1978), "Wind tunnel experiments on aerodynamic forces and pressure distributions of rectangular cylinders in a uniform flow"(in Japanese), Proceedings of the Fifth Symposium on Wind Effects on Structures, Tokyo, Japan.
  30. Pocha, J.J. (1971), "On unsteady flow past cylinders of square cross-section", Ph.D. Dissertation, University of London, London.
  31. Schewe, G. (1983),"On the force fluctuations acting on a circular cylinder in crossflow from subcritical up to transcritical Reynolds numbers", J. Fluid Mech., 133, 265-285. https://doi.org/10.1017/S0022112083001913
  32. Schewe, G. (1986),"Sensitivity of transition phenomena to small perturbations in flow round a circular cylinder", J. Fluid Mech.,172, 33-46. https://doi.org/10.1017/S0022112086001635
  33. Shimada, K. and Ishihara, T. (2002), "Application of a modified k-${\varepsilon}$ model to the prediction of aerodynamic characteristics of rectangular cross-section cylinders", J. Fluid. Struct., 16(4), 465-485. https://doi.org/10.1006/jfls.2001.0433
  34. Sohankar, A., Davidson, L. and Norberg, C. (2000), "Large eddy simulation of flow past a square cylinder: Comparison of different subgrid scale models", J. Fluid. Eng.-T. ASME, 122(1), 39-47. https://doi.org/10.1115/1.483224
  35. Tamura, T. and Kuwahara, K. (1990), "Numerical study of aerodynamic behavior of a square cylinder", J. Wind Eng. Ind. Aerod., 33(1), 161-170. https://doi.org/10.1016/0167-6105(90)90032-8
  36. Tamura, T. and Miyagi, T. (1999), "The effect of turbulence on aerodynamic forces on a square cylinder with various corner shapes", J. Wind Eng. Ind. Aerod., 83(1), 135-145. https://doi.org/10.1016/S0167-6105(99)00067-7
  37. Tamura, T., Miyagi, T. and Kitagishi, T. (1998), "Numerical prediction of unsteady pressures on a square cylinder with various corner shapes", J. Wind Eng. Ind. Aerod., 74, 531-542.
  38. Tamura, T., Ohta, I. and Kuwahara, K. (1990), "On the reliability of two-dimensional simulation for unsteady flows around a cylinder-type structure", J. Wind Eng. Ind. Aerod., 35, 275-298. https://doi.org/10.1016/0167-6105(90)90221-W
  39. Taylor, I. and Vezza, M. (1999), "Prediction of unsteady flow around square and rectangular section cylinders using a discrete vortex method", J. Wind Eng. Ind. Aerod., 82(1), 247-269. https://doi.org/10.1016/S0167-6105(99)00038-0
  40. Vickery, B.J. (1966), "Fluctuating lift and drag on a long cylinder of square cross-section in a smooth and in a turbulent stream", J. Fluid Mech., 25(3), 481-494. https://doi.org/10.1017/S002211206600020X
  41. Wang, J.M., Cheng, C.M. and Tens, P.T. (2003), "Design wind loads on tall buildings: a wind tunnel data based expert system approach", Proceedings of 11th International Conference on Wind Engineering. Lubbock, TX, USA.
  42. Wang, X. and Gu, M. (2015),"Experimental investigation of Reynolds number effects on 2D rectangular prisms with various side ratios and rounded corners", Wind Struct., 21(2), 183-202. https://doi.org/10.12989/was.2015.21.2.183
  43. Yen, S.C. and Yang, C.W. (2011), "Flow patterns and vortex shedding behavior behind a square cylinder", J. Wind Eng. Ind. Aerod., 99(8), 868-878. https://doi.org/10.1016/j.jweia.2011.06.006
  44. Yu, D.H. and Kareem, A. (1996), "Two-dimensional simulation of flow around rectangular prisms", J. Wind Eng. Ind. Aerod., 62(2), 131-161. https://doi.org/10.1016/S0167-6105(96)00076-1
  45. Yu, D.H. and Kareem, A. (1997), "Numerical simulation of flow around rectangular prism", J. Wind Eng. Ind. Aerod., 67, 195-208.

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