Figure 2 Idea and details of T-shaped weir.

Behzad NorooziJalal BazarganAkbar Safarzadeh

Abstract

본 연구에서는 LW(Labyrinth Weir)와 PKW(Piano Key Weir)가 결합된 T자형 웨어(TSW)라는 새로운 비선형 웨어를 도입하여 수압 성능을 비교하였다.

PKW. 입구 키, 출구 키 또는 두 키 모두에서 수직 벽의 존재에 따라 TSW 위어는 각각 A, B 또는 C 유형 웨어로 분류되었습니다. 다른 TSW 사례의 흐름 패턴을 분석하고 배출 계수 곡선을 제공했습니다. 또한 테스트된 둑의 유체역학을 정확하게 연구하기 위해 FLOW-3D 소프트웨어를 사용하여 3D 수치 시뮬레이션을 수행했습니다.

결과는 출구 키(C-TSW 유형)의 상류에 수직 벽을 삽입하는 것이 PKW의 유압 성능에 미미한 영향을 미치는 것으로 나타났습니다. B-TSW의 토출계수는 PKW 대비 최대 16% 증가하였으며, Ht/p 0.45까지 수직벽의 성능향상 효과 증가 B-TSW는 유지되었습니다.

실험적 및 수치적 실험을 통해 가장 높은 방전 용량을 갖는 B-TSW에서 수직벽의 최적 높이비(Pd/P)는 0.4로 결정되었다.

In the present study, a new nonlinear weir called the T-shaped weir (TSW), which is a combination of the labyrinth weir (LW) and the piano key weir (PKW), was introduced, and its hydraulic performance was compared with the PKW. Based on the presence of the vertical walls at the inlet key, outlet key, or both keys, the TSW weirs were classified as type A, B, or C weirs, respectively. The flow pattern of different TSW cases was analyzed, and the discharge coefficient curves were provided. Furthermore, to accurately study the hydrodynamics of the tested weirs, 3D numerical simulations were performed using the FLOW-3D software. The results showed that inserting a vertical wall at the upstream of the outlet keys (C-TSW type) has a negligible effect on the hydraulic performance of the PKW. A maximum increase of 16% occurred in the discharge coefficient of the B-TSW in comparison to the PKW, and up to a head to height ratio (Ht/p) of 0.45, the effect of the vertical wall on increasing the performance of the B-TSW was maintained. Based on the experimental and numerical tests, the optimal height ratio of the vertical wall (Pd/P) in B-TSW with highest discharge capacity was determined to be equal to 0.4.

HIGHLIGHTS

Listen

  • A new nonlinear weir called the T-shaped weir (TSW), which is a combination of the labyrinth weir (LW) and the piano key weir (PKW), is introduced.
  • To investigate the hydrodynamics of the tested weirs in more detail, 3D numerical models are developed on the CFD-software FLOW-3D.
  • By testing different vertical wall sizes, the optimal size of the vertical wall is determined for B-TSW weir.

Keywords

discharge coefficientlabyrinth weirlocal submergencepiano key weirT-shaped weir

Figure 2 Idea and details of T-shaped weir.
Figure 2 Idea and details of T-shaped weir.

Figure 19. Water surface profile at the middle part of the inlet key for H/P = 0.4.
Figure 19. Water surface profile at the middle part of the inlet key for H/P = 0.4.
Figure 21 Transverse water surface profile in the outlet key of tested weirs  for H/P = 0.4.
Figure 21 Transverse water surface profile in the outlet key of tested weirs for H/P = 0.4.

REFERENCES

Anderson R. M. & Tullis B. P. 2011 Influence of Piano Key Weirs Geometry on Discharge. In Labyrinth and Piano Key Weirs – PKW 2011. CRC Press, Leiden, pp. 75–80.

Anderson R. M. & Tullis B. P. 2012 Comparison of piano key and rectangular labyrinth weir hydraulics. Journal of Hydraulic Engineering 138 (4), 358–361.

Azamathulla H. M., Haghiabi A. H. & Parsaie A. 2016 Prediction of side weir discharge coefficient by support vector machine technique. Water Science and Technology: Water Supply 16 (4), 1002–1016.

Bremer F. L. & Oertel M. 2017 Numerical investigation of wall thickness influence on Piano key Weir discharge coefficients: A preliminary study. In Labyrinth and Piano Key Weirs III – PKW 2017. CRC Press, London, UK, pp. 101–108.

Cicero G. M., Delisle J. R., Lefebvre V. & Vermeulen J. 2013 Experimental and Numerical Study of the Hydraulic Performance of A Trapezoidal PKW. In Labyrinths and Piano Key Weirs PKW 2013. CRC Press, Boca Raton, FL, pp. 265–272.

Crookston B. & Tullis B. 2012 Labyrinth Weirs: Nappe interference and local submergence. Journal of Irrigation and Drainage Engineering 138 (8), 757–765.

Crookston B., Anderson R. M. & Tullis B. P. 2017 Free-flow discharge estimation method for piano key weir geometries. Journal of Hydro-Environment Research 19, 60–167.

Ghasemlounia R. & Saghebian S. M. 2021 Uncertainty assessment of kernel based approaches on scour depth modeling in downstream of ski-jump bucket spillways. Water Supply 21 (5), 2333–2346. doi:10.2166/ws.2021.063.

Kabiri-Samani A. & Javaheri A. 2012 Discharge coefficients for free and submerged flow over piano key weirs. Journal of Hydraulic Research 50 (1), 114–120.

Lefebvre V., Vermeulen J. & Blancher B. 2013 Influence of Geometrical Parameters on PK-Weirs Discharge with 3D Numerical Analysis. In: Labyrinth and Piano key Weirs II – PKW 2013. CRC Press, London, pp. 49–56.

Lempérière F. & Ouamane A. 2003 The piano keys weir: a new cost-effective solution for spillways. International Journal on Hydropower & Dams 10 (5), 144–149.

Machiels O., Erpicum S., Archambeau P., Dewals B. J. & Pirotton M. 2011 Influence of piano key weir height on its discharge capacity. In Proc. Int. Conf. Labyrinth and Piano Key Weirs Liège B, pp. 59–66.

Machiels O., Pirotton M., Pierre A., Dewals B. & Erpicum S. 2014 Experimental parametric study and design of piano key weirs. Journal of Hydraulic Research 52 (3), 326–335.

Parsaie A., Azamathulla H. M. & Haghiabi A. H. 2018 Prediction of discharge coefficient of cylindrical weir-gate using GMDH-PSO. ISH Journal of Hydraulic Engineering 24 (2), 116–123.

Paxson G. & Savage B. 2006 Labyrinth spillways: comparison of two popular USA design methods and consideration of non-standard approach conditions and geometries. Division of Civil Engineering, p.37.

Pourshahbaz H., Abbasi S., Pandey M., Pu J. H., Taghvaei P. & Tofangdar N. 2020 Morphology and hydrodynamics numerical simulation around groynes. ISH Journal of Hydraulic Engineering 1–9.

Pralong J., Vermeulen J., Blancher B., Laugier F., Erpicum S., Machiels O., Pirotton M., Boillat J.-L., Leite Ribeiro M. & Schleiss A. 2011a A naming convention for the Piano Key Weirs geometrical parameters. In Labyrinth and Piano key Weirs – PKW 2011. CRC Press, London, pp. 271–278.

Pralong J., Montarros F., Blancher B. & Laugier F. 2011b A sensitivity analysis of Piano Key Weirs geometrical parameters based on 3D numerical modelling. In Labyrinth and Piano key Weirs – PKW 2011. CRC Press, London, pp. 133–139.

Ribeiro M. L., Bieri M., Boillat J. L., Schleiss A., Delorme F. & Laugier F. 2009 Hydraulic capacity improvement of existing spillways–design of a piano key weir. In Proceedings (on CD) of the 23rd Congress of the Int. Commission on Large Dams CIGB-ICOLD, Brasilia, Vol. 2, No. CONF, pp. 100–118.

Ribeiro M. L., Pfister M., Schleiss A. J. & Boillat J. L. 2012 Hydraulic design of A-type piano key weirs. Journal of Hydraulic Research 50 (4), 400–408.

Roache P. 1994 Perspective: a method for uniform reporting of grid refinement studies. Journal of Fluids Engineering 116 (3), 405–413.

Safarzadeh A. & Mohajeri S. H. 2018 Hydrodynamics of rectangular broad-crested porous weirs. Journal of Irrigation and Drainage Engineering 144 (10), 04018028.

Safarzadeh A. & Noroozi B. 2014 Three dimensional hydrodynamics of arced piano key spillways. Journal of Hydraulics 9 (3), 61–79.

Safarzadeh A. & Noroozi B. 2017 3D hydrodynamics of trapezoidal piano key spillways. International Journal of Civil Engineering 15 (1), 89–101.

Safarzadeh A., Zaji A. H. & Bonakdari H. 2017 Comparative assessment of the hybrid genetic algorithm–artificial neural network and genetic programming methods for the prediction of longitudinal velocity field around a single straight groyne. Applied Soft Computing 60, 213–228.

Tullis B. P., Young J. C. & Chandler M. A. 2007 Head-discharge relationships for submerged labyrinth weirs. Journal of Hydraulic Engineering 133 (3), 248–254.

Xinlei G., Zhiping L., Tao Wang H., Jiazhen L., Qingfu X. & Yongxin G. 2019 Discharge capacity evaluation and hydraulic design of a piano key weir. Water Supply 19 (3), 871–878.

Zahiri A., Azamathulla H. M. & Bagheri S. 2013 Discharge coefficient for compound sharp crested side weirs in subcritical flow conditions. Journal of Hydrology 480, 162–166.

Zahiri A., Tang X. & Azamathulla H. M. 2014 Mathematical modeling of flow discharge over compound sharp-crested weirs. Journal of Hydro-Environment Research 8 (3), 194–199.