대한토목학회논문집 (KSCE Journal of Civil and Environmental Engineering Research)

  • 제26권6B호
  • /
  • Pages.573-581
  • /
  • 2006
  • /
  • 1015-6348(pISSN)
  • /
  • 2799-9629(eISSN)
대한토목학회 (Korean Society of Civil Engeneers)
권호 표지
DOI QR코드

DOI QR Code

매끄러운 하상-거친 하상의 횡방향 연속구조를 갖는 개수로 흐름의 3차원 수치모의

3-D Numerical Simulation of Open-Channel Flows over Smooth-Rough Bed Strips

  • 최성욱 (연세대학교 사회환경시스템공학부) ;
  • 박문형 (연세대학교 사회환경시스템공학부) ;
  • 강형식 (연세대학교 사회환경시스템공학부)
  • 투고 : 2005.06.09
  • 심사 : 2006.09.20
  • 발행 : 2006.11.29
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

본 연구에서는 레이놀즈응력모형을 이용하여 매끄러운 하상-거친 하상의 횡방향 연속구조를 갖는 개수로 흐름을 수치모의하였다. 개발된 모형을 이용하여 평균유속 및 난류량을 계산하고 기존의 실험결과와 비교하였다. 그 결과 레이놀즈응력모형이 매끄러운 하상-거친 하상의 횡방향 연속구조를 갖는 개수로 흐름에서의 평균유속과 난류구조를 비교적 유사하게 예측하는 것으로 나타났다. 특히 이차흐름 벡터도를 계산한 결과 매끄러운 하상에서는 상향류가, 거친 하상에서는 하향류가 나타나는 격자형 이차흐름이 발생하였으며, 이와 같은 격자형 이차흐름은 평균유속 및 난류량 분포에 큰 영향을 미치는 것을 확인하였다. 또한 와도 방정식의 각 항을 비교하여 개수로 흐름에서의 이차흐름의 성인(成因)을 분석하였다.

This paper presents a turbulence modeling of the open-channel flows over smooth-rough bed strips. A Reynolds stress model is used for the turbulence closure. The simulated mean flow and turbulence structures are compared with the previously reported experimental data. Comparisons reveal that the developed Reynolds stress model successfully predicts the mean flow and turbulence structures of open-channel flows over smooth-rough bed strips. The computed flow vectors show cellular secondary currents, of which the upflow occurs over the smooth bed strip and the downflow over the rough bed strip. It is found that the cellular secondary currents affect the mean flow and turbulence structure. A budget analysis of the streamwise vorticity equation is also carried out to investigate the mechanism by which the secondary currents are generated.

키워드

참고문헌

  1. 강형식, 최성욱(2002) 개수로 흐름에서 레이놀즈응력모형의 비교. 대한토목학회논문집, 대한토목학회, 제22권 제1-B호, pp. 21-32
  2. Demuran, A.O. and Rodi, W. (1984) Calculation of turbulence driven secondary motion on non circular ducts. Journal of Fluid Mechanics, 140, pp. 189-222 https://doi.org/10.1017/S0022112084000574
  3. Gessner, F.B. (1973) The origin of secondary flow in turbulent flow along a corner. Journal of Fluid Mechanics, 58, pp. 1-25 https://doi.org/10.1017/S0022112073002090
  4. Gessner, B.F. and Jones, J.B, (1965) On some aspects of fully developed turbulent flow in rectangular channels. Journal of Fluid Mechanics, 23, 689 https://doi.org/10.1017/S0022112065001635
  5. Gibson, M.M. and Launder, B.E. (1978) Ground effects on pressure fluctuations in the atmospheric boundary layer. Journal of Fluid Mechanics, 86, pp. 491-511 https://doi.org/10.1017/S0022112078001251
  6. Hanjalic, K. and Launder, B.E. (1972) A Reynolds stress model of turbulence and its application to thin shear flows. Journal of Fluid Mechanics, 52, pp. 609-638 https://doi.org/10.1017/S002211207200268X
  7. Hossain, M.S. and Rodi, W. (1980) Mathematical modeling of vertical mixing in stratified channel flow. Proceedings of the 2nd Symposium on Stratified Flows
  8. Huser, A. and Biringen, S. (1993) Direct numerical simulation of turbulent flow in a square duct. Journal of Fluid Mechanics, 257, pp. 65-95 https://doi.org/10.1017/S002211209300299X
  9. Kang, H. And Choi, S.-U. (2005) Reynolds stress modeling of rectangular open-channel flows. International Journal for Numerical Methods in Fluids, Vol. 51, No. 11, pp. 1319-1334 https://doi.org/10.1002/fld.1157
  10. Lin, C.A. (1990) Three dimensional computations of injection into swirling cross flow using second moment closure. Ph.D. Thesis, UMIST, Manchester, England
  11. McLean, S.R. (1981) The role of non uniform roughness in the formation of sand ribbons. Marine Geology, 42, pp. 49-74 https://doi.org/10.1016/0025-3227(81)90158-4
  12. McLelland, S.J., Ashworth, P.J., Best, J.L., and Livesey, J.R. (1999) Turbulence and secondary flow over sediment strips in weakly bimodal bed material. Journal of Hydraulic Engineering, ASCE, Vol. 125, No.5, pp. 463-473 https://doi.org/10.1061/(ASCE)0733-9429(1999)125:5(463)
  13. Mellor, G.L. and Herring, H.J. (1973) A survey of mean turbulent field closure. AIM Journal, II, pp. 590-599
  14. Meyer-Peter, E. and Muller, R. (1948) Formulas for bedload transport Proceedings of the 2nd Congress of the International Association jar Hydraulic Research, Stockholm, pp. 39-64
  15. Muller, A. and Studerus, X. (1979) Secondary flow in an open-channel. Proc. of 18th IAHR congress, Cagliari, 3, pp. 19-24
  16. Nezu, I. and Nakagawa, H. (1993) Turbulence in open-channel flows. Monograph, Balkema, Rotterdam, The Netherland
  17. Nezu, I. and Nakagawa, H. (1993) Cellular secondary currents in straight conduit. Journal of Hydraulic Engineering, ASCE, Vol. 110, No.2, pp. 173-193 https://doi.org/10.1061/(ASCE)0733-9429(1984)110:2(173)
  18. Naot, D. (1984) Response of channel flow to roughness heterogeneity. Journal of Hydraulic Engineering, ASCE, Vol. 110, No. 11, pp.1568-1587 https://doi.org/10.1061/(ASCE)0733-9429(1984)110:11(1568)
  19. Naot, D. and Emrani, S. (1983) Numerical simulation of the hydrodynamic behavior of fuel rod with longitudinal cooling fins. Nuclear Engrs. and Des., 73, pp. 319-329
  20. Naot, D. and Rodi, W. (1982) Calculation of secondary currents in channel flows. Journal of the Hydraulic Division, ASCE, 108(HY8), pp. 948-968
  21. Nakagawa, H., Nezu, I., and Tominaga, A. (1981) Turbulent structure with and without cellular secondary currents over various bed configurations. Annuals, Disaster Prevention Research Institute, Kyoto University, 24B, pp. 315-338 (in Japaness)
  22. Ohmoto, T. and Hayashi, S. (2003) Study of generation mechanism of secondary currents in open-channel flow by direct numerical simulation. Journal of Hydroscience and Hydraulic Engineering, Vol. 21, No.1, pp.11-21
  23. Sofialidis, D. and Prinos, P. (1998) Compound open-channel flow modeling with nonlinear low-Reynolds k-e models. Journal of Hydraulic Engineering, ASCE, Vol. 124, No.3, pp. 253-262 https://doi.org/10.1061/(ASCE)0733-9429(1998)124:3(253)
  24. Speziale, C.G., Sarkar, S., and Gatski, T. (1991) Modeling the pressure strain correlation of turbulence: an invariant dynamical systems approach. Journal of Fluid Mechanics, 227, pp. 245-272 https://doi.org/10.1017/S0022112091000101
  25. Studerus, X. (1982) Sekundarstomungen im offenen gerinne rauhen Langssteinfen. Ph.D. Thesis, Institut fur Hydromechanik und Wasserwirtschaft, ETH, Zurich, Switzerland
  26. Vanoni, VA. (1946) Transportation of suspended sediment by water. Trans. of ASCE, 111, pp. 67-133
  27. Wang, Z.-Q., Cheng, N.S., Chiew, Y.M., and Chen, X.W. (2003) Secondary flows in open-channel with smooth and rough bed strips. Proceedings of 30th IAHR Congress, Thessaloniki, Greece, Theme C, pp. 111-118
  28. Wang, Z.-Q. And Cheng, N.-S. (2005) Secondary flows over artificial bed strips. Advances in Water Resources, 28, pp. 441-450 https://doi.org/10.1016/j.advwatres.2004.12.008