Journal of Korea Water Resources Association (한국수자원학회논문집)

Korea Water Resources Association (한국수자원학회)
권호 표지
DOI QR코드

DOI QR Code

Measurements of turbulent flows downstream of a spur dike at different Froude numbers

Froude 수 변화에 따른 수제 하류 난류 흐름 측정

  • Lee, Jiyong (Department of Civil and Environmental Engineering, Hanyang University) ;
  • Kim, Yeongkyu (Department of Civil and Environmental Engineering, Hanyang University) ;
  • Cha, Jun-Ho (Han River Flood Control Office, Ministry of Environment) ;
  • Kang, Seokkoo (Department of Civil and Environmental Engineering, Hanyang University)
  • 이지용 (한양대학교 공과대학 건설환경공학과) ;
  • 김영규 (한양대학교 공과대학 건설환경공학과) ;
  • 차준호 (한강홍수통제소 수자원정보센터) ;
  • 강석구 (한양대학교 공과대학 건설환경공학과)
  • Received : 2018.10.12
  • Accepted : 2018.12.19
  • Published : 2019.02.28
Download PDF
⟨ Previous Next ⟩

Abstract

The effects of the Froude numbers on turbulent flow patterns downstream of a non-submerged spur dike were investigated in a laboratory flume. Three-dimensional velocities and water depths were measured using Acoustic Doppler Velocimetry and distance sensors under three Froude number conditions ($Fr_d=0.31$, 0.38, and 0.46). The results show that there are marginal differences in the velocity fields downstream of a spur dike due to the change of the Froude number. However, an increase of the Froude number was found to reduce cross-sectional area in the flow and to increase the strength of the jet-like flow. The jet-like flow was observed to displace the location of the maximum turbulence kinetic energy within a cross section toward the inner bank in the transverse direction.

잠기지 않은 수제 하류의 3차원 흐름구조에 Froude 수 변화가 미치는 영향을 알아보기 위한 수리모형 실험을 수행하였다. 3가지 Froude 수 조건에 대하여 초음파 유속계와 수위계를 이용하여 3차원 유속과 수심을 측정하였다. Froude 수는 시간평균유속 및 난류 특성의 전반적인 분포에는 크게 영향을 미치지 않는 것으로 나타났다. 그러나 Froude 수가 증가할수록 수제 위치의 흐름단면이 감소하고 제트 흐름 강도의 증가가 관찰되었다. 이 제트 흐름은 단면 내 최대 난류에너지 발생의 위치를 안쪽 제방으로 이동시키는 것으로 나타났다.

Keywords

SJOHCI_2019_v52n2_115_f0001.png 이미지

Fig. 1. Experiment equipment: ADV and a spur dike

SJOHCI_2019_v52n2_115_f0002.png 이미지

Fig. 2. Three-dimensional schematic view of the experiment

SJOHCI_2019_v52n2_115_f0003.png 이미지

Fig. 3. Measurement locations

SJOHCI_2019_v52n2_115_f0004.png 이미지

Fig. 4. Time-averaged water elevation profiles along the streamwise direction at y /L = 1.33

SJOHCI_2019_v52n2_115_f0005.png 이미지

Fig. 5. Dimensionless time-averaged streamwise velocity (u /U0) profiles at z /Hd = 0.08 (top) and z /Hd = 0.23 (bottom)

SJOHCI_2019_v52n2_115_f0006.png 이미지

Fig. 6. Dimensionless time-averaged spanwise velocity (v /U0) profiles at z /Hd = 0.08 (top) and z /Hd = 0.23 (bottom)

SJOHCI_2019_v52n2_115_f0007.png 이미지

Fig. 7. Dimensionless time-averaged vertical velocity (w /U0) profiles at z /Hd = 0.08 (top) and z /Hd = 0.23 (bottom)

SJOHCI_2019_v52n2_115_f0008.png 이미지

Fig. 8. Dimensionless time-averaged turbulence kinetic energy (k /U02) profiles at z /Hd = 0.08 (top) and z /Hd = 0.23 (bottom)

Table 1. Experimental and numerical parameters of previous research works for a non-submerged spur dike

SJOHCI_2019_v52n2_115_t0001.png 이미지

Table 2. Experimental parameters of the present experiment at x = 0.15 m (x /L = 0.5)

SJOHCI_2019_v52n2_115_t0002.png 이미지

References

  1. Dey, S., and Barbhuiya, A. K. (2006). "Velocity and turbulence in a scour hole at a vertical-wall abutment." Flow Measurement and Instrumentation, Vol. 17, No. 1, pp. 13-21. https://doi.org/10.1016/j.flowmeasinst.2005.08.005
  2. Duan, J. G. (2009). "Mean flow and turbulence around a laboratory spur dike." Journal of Hydraulic Engineering, Vol. 135, No. 10, pp. 803-811. https://doi.org/10.1061/(ASCE)HY.1943-7900.0000077
  3. Duan, J. G., He, L., Fu, X., and Wang, Q. (2009). "Mean flow and turbulence around experimental spur dike." Advances in Water Resources, Vol. 32, No. 12, pp. 1717-1725. https://doi.org/10.1016/j.advwatres.2009.09.004
  4. Jeon, J. S., and Kang, S. K. (2016). "Flume experiments for turbulent flow around a spur dike" Journal of Korea Water Resources Association, Vol. 49, No. 8, pp. 707-717. https://doi.org/10.3741/JKWRA.2016.49.8.707
  5. Jeon, J. S., Lee, J. Y., and Kang, S. K. (2018). "Experimental investigation of three-dimensional flow structure and turbulent flow mechanisms around a nonsubmerged spur dike with a low length-to-depth ratio." Water Resources Research, Vol. 54, No. 5, pp. 3530-3556. https://doi.org/10.1029/2017WR021582
  6. Kuhnel, R. A., Alonso, C. V., and Shields, F. D. (1999). "Geometry of scour holes associated with 90 degree spur dike." Journal of Hydraulic Engineering, Vol. 125, No. 9, pp. 972-978. https://doi.org/10.1061/(ASCE)0733-9429(1999)125:9(972)
  7. Kang, J. G., Yeo, H. K., and Kim, S. J. (2005). "An experimental study on tip velocity and downstream recirculation zone of single groyne conditions." Journal of Korea Water Resources Association, Vol. 38, No. 2, pp. 143-153. https://doi.org/10.3741/JKWRA.2005.38.2.143
  8. Koken, M., and Constantinescu, G. (2008). "An investigation of the flow and scour mechanisms around isolated spur dikes in a shallow open channel: 1. Conditions corresponding to the initiation of the erosion and deposition process." Water Resources Research, Vol. 44, No. 8, pp. 1-19.
  9. Kang, J. G., Kim, S. J., and Yeo, H. K. (2009). "An experimental study on flow characteristic around inclined crest groyne." Journal of Korea Water Resources Association, Vol. 42, No. 9, pp. 715-724. https://doi.org/10.3741/JKWRA.2009.42.9.715
  10. Kim, S. J., Kang, J. G., and Yeo, H. K. (2014). "An experimental study on flow characteristics for optimal spacing suggestion of $45^{\circ}$ upward groynes." Journal of Korea Water Resources Association, Vol. 47, No. 5, pp. 459-468. https://doi.org/10.3741/JKWRA.2014.47.5.459
  11. Kara, S., Kara, M. C., Stoesser, T., and Sturm, T. W. (2015). "Freesurface versus rigid-lid LES computations for bridge-abutment flow." Journal of Hydraulic Engineering, Vol. 141, No. 9, 04015019, pp. 1-9.
  12. Khosronejad, A., Ghazian Arabi, M., Angelidis, D., Bagherizadeh, E., Flora, K., and Farhadzadeh, A. (2018). "Comparative hydrodynamic study of rigid-lid and level-set methods for LES of openchannel flow." Journal of Hydraulic Engineering, Vol. 145, No. 1, 04018077, pp. 1-15.
  13. Lee, J. Y., Jeon, J. S., Kim, Y. K., and Kang, S. K. (2018). "Flume experiments for studying the effects of submerged-conditions on three-dimensional flow structure around a spur dike." Journal of Korea Water Resources Association, Vol. 51, No. 2, pp. 109-120. https://doi.org/10.3741/JKWRA.2018.51.2.109
  14. Paik, J., and Sotiropoulos, F. (2005). "Coherent structure dynamics upstream of a long rectangular block at the side of a large aspect ratio channel." Physics of fluids, Vol. 17, No. 11, pp. 1-14 (115104). https://doi.org/10.1063/1.1694570
  15. Rajaratnam, N., and Nwachukwu, B.A. (1983). "Flow near groinlike structures." Journal of Hydraulic Engineering, Vol. 109, No. 3, pp. 463-480. https://doi.org/10.1061/(ASCE)0733-9429(1983)109:3(463)
  16. Rajaratnam, N., and Nwachukwu, B.A. (1983). "Erosion near groin-like structures." Journal of Hydraulic Engineering, Vol. 21, No. 4, pp. 277-287.
  17. Safarzadeh, A., Salehi Neyshabouri, S. A. A., and Zarrati, A. R. (2016). "Experimental investigation on 3D turbulent flow around straight and T-shaped groynes in a flat bed channel." Journal of Hydraulic Engineering, Vol. 142 No. 8, pp. 1-15 (04016021).
  18. Yeo, H. K., Roh, Y. S., Kang, J. G., and Kim, S. J. (2006). "Variations of flow thalweg alignment and separation region around a groyne." Journal of Korea Water Resources Association, Vol. 39, No. 4, pp. 313-320. https://doi.org/10.3741/JKWRA.2006.39.4.313