Effect of Different Channels on Discharge Coefficient of Labyrinth Weirs

In this study, the effect of channel-bed slope and non-prismatic converging channel on the discharge coefficient of labyrinth weirs is numerically investigated utilizing FLOW-3D model. Numerical simulation results show that modifying the labyrinth weir channel through both methods improves the discharge coefficient. Among the selected bed slopes and converging channel wall, the slope of β=4% and angle of θ=10° yielded the highest discharge coefficient. For a ratio HT/P=0.1, (HT: flow height, P: weir height) the discharge coefficient and discharge rate for bed slope and convergence angle case were 19.22%, 23.9% and 22.28%, 25.91% higher than for a conventional labyrinth weir in prismatic channel, respectively. Simultaneous application of a bed slope and convergence angle significantly increases the discharge coefficient and discharge value case were 28.64% and 30.42% higher than compared to the conventional case. Therefore, changing the bed slope and wall angle of the weir channel increases the discharge coefficient and in this type of weir and these design alterations should be considered in weir design.

Effect of Different Channels on Discharge Coefficient of Labyrinth Weirs

In this study, the effect of channel-bed slope and non-prismatic converging channel on the discharge coefficient of labyrinth weirs is numerically investigated utilizing FLOW-3D model. Numerical simulation results show that modifying the labyrinth weir channel through both methods improves the discharge coefficient. Among the selected bed slopes and converging channel wall, the slope of β=4% and angle of θ=10° yielded the highest discharge coefficient. For a ratio HT/P=0.1, (HT: flow height, P: weir height) the discharge coefficient and discharge rate for bed slope and convergence angle case were 19.22%, 23.9% and 22.28%, 25.91% higher than for a conventional labyrinth weir in prismatic channel, respectively. Simultaneous application of a bed slope and convergence angle significantly increases the discharge coefficient and discharge value case were 28.64% and 30.42% higher than compared to the conventional case. Therefore, changing the bed slope and wall angle of the weir channel increases the discharge coefficient and in this type of weir and these design alterations should be considered in weir design.

___

  • [1] Taylor, G., The performance of labyrinth weirs, PhD thesis. Univ. of Nottingham, U.K.J. 1968.
  • [2] Hay, N., Taylor, G., Performance and design of labyrinth weirs. ASCE, Journal of Hydraulic Engineering, Vol 96, No 11, 2337-2357, 1970.
  • [3] Magalhães, A., Lorena, M., Hydraulic design of labyrinth weirs. Report No. 736, National Laboratory of Civil Engineering, Lisbon, Portugal. 1989.
  • [4] Lux, F., and Hinchliff, D., Design and construction of labyrinth spillways. 15thCongress ICOLD, Vol. IV, Q59-R15, Lausanne, Switzerland, 249-274, 1985.
  • [5] Tullis, J.P., Nosratollah, A., Waldron, D., Design of labyrinth weirs, ASCE, Journal of Hydraulic Engineering, Vol 121, No 3, 247-255, 1995.
  • [6] Melo, J., Ramos, C., Magalhaes, A., Descarregadores com soleira em labirinto de um ciclo em canais convergentes. Determinação da capacidad de vazão, Proc. 6° Congresso da Água, Porto, Portugal, in Portuguese. 2002.
  • [7] Tullis, B., Young, J., Chandler, M., Head-discharge relationships for submerged labyrinth weirs. Journal of Hydraulic Engineering, Vol 133, No 3, 248-254. 2007.
  • [8] Anderson, R.M., Tullis, B.P., Comparison of piano key and rectangular labyrinth weir hydraulics. ASCE, Journal of Hydraulic Engineering, Vol 138, No 4, 358-361, 2011.
  • [9] Carollo, G.F, Ferro V., Pampalone, V., ¬Experimental Investigation of the Outflow Process over a Triangular Labyrinth-Weir. ASCE, Journal of Irrigation and Drainage Engineering, Vol 138, No 1, 73-79. 2012.
  • [10] Khode, BV., Tembhurkar, AR., Porey, PD., Ingle, RN., Experimental Studies on Flow over Labyrinth Weir, Journal of Irrigation and Drainage Engineering, Vol 138, No 6, 548-552, ¬2012.
  • [11] Bilhan, O., Emiroglu, M. E., Miller, C.J., Experimental Investigation of Discharge Capacity of Labyrinth Weirs with and without Nappe Breakers. World Journal of Mechanics, Vol 6, 207-221, 2016.
  • [12] Daneshfaraz, R., Ghahramanzadeh, A., Ghaderi, A., Joudi, A. R., Abraham, J., Investigation of the Effect of Edge Shape on Characteristics of Flow under Vertical Gates, Journal‐American Water Works Association, Vol 108, No 8, 425-432, 2016.
  • [13] Ghaderi, A., Dasineh, M., Abbasi, S., Abraham, J., Investigation of trapezoidal sharp-crested side weir discharge coefficients under subcritical flow regimes using CFD, Applied Water Science, Vol 10, No 1, 31, 2020
  • [14] Savage, B., Frizell, K., Crowder, J., Brian versus brawn: The changing world of hydraulic model studies. Proc. of the ASDSO Annual Conference, Phoenix, Ariz., CD-ROM, 2004.
  • [15] Daneshfaraz, R., Joudi, A. R., Ghahramanzadeh, A., Ghaderi, A., Investigation of flow pressure distribution over a stepped weir, Advances and Applications in Fluid Mechanics, Vol 19, No 4, 811, 2016.
  • [16] Daneshfaraz, R., Minaei, O., Abraham, J., Dadashi, S., Ghaderi, A., 3-D Numerical simulation of water flow over a broad-crested weir with openings, ISH Journal of Hydraulic Engineering, 1-9, 2019.
  • [17] Dabling, M.R., Tullis, B.P., Modifying the downstream hydrograph with staged labyrinth weirs. Journal of Applied Water Engineering and Research, Vol 6, No3, 183-190. 2018).
  • [18] Shaghaghian, M.R., Sharifi, M.T., Numerical modeling of sharp-crested triangular plan form weirs using FLUENT. Indian Journal of Science and Technology, Vol 8, No, 34, 1-7. 2015.
  • [19] Norouzi, R., Daneshfaraz, R., Ghaderi, A., Investigation of discharge coefficient of trapezoidal labyrinth weirs using artificial neural networks and support vector machines. Applied Water Science, Vol 9, No 7, 148. 2019.
  • [20] Daneshfaraz, R., Ghaderi, A., Ghahremanzadeh, A. An analysis of flowing pattern around T-shaped Spur Dike at 90 Arc, based on Fluent and Flow-3D Models. International Bulletin of Water Resources and Development, Vol 3, No 3, 1-9. 2015.
  • [21] Hirt, C. W. and Nichols, B. D., Volume of Fluid (VOF) method for the dynamics of free boundaries. Journal of Computational Physics, 39:201–225, 1981.
  • [22] Flow Science, Inc. FLOW-3D User Manual. Version 11.0.3, Santa Fe, New Mexico, USA, 2014.
  • [23] Ghaderi, A., Abbasi, S. CFD simulation of local scouring around airfoil-shaped bridge piers with and without collar. Sādhanā, Vol 44, No, 10, 216, 2019.
  • [24] Zahabi, H., Torabi, M., Alamatian, E., Bahiraei, M., Goodarzi, M. Effects of Geometry and Hydraulic Characteristics of Shallow Reservoirs on Sediment Entrapment. Water, Vol 10, No 12, 1725, 2018.
  • [25] Seo, I.W., Do Kim Y., Park Y.S., Song C.G., Weir discharges by modification of weir shapes and overflow surroundings, Environmental Earth Sciences, Vol 75, No 6, 496, 2016.
  • [26] Daneshfaraz, R., Ghaderi, A., Numerical Investigation of Inverse Curvature Ogee Weir, Civil Engineering Journal, Vol 3, No 11, 1146-1156, 2017.
  • [27] Daneshfaraz, R., Sadeghfam, S., Ghahramanzadeh, A., Three-dimensional numerical investigation of flow through screens as energy dissipators. Canadian Journal of Civil Engineering, Vol 44, No 10, 850-859, 2017.
  • [28] Ghaderi, A., Dasineh, M., Daneshfaraz, R., Abraham, J., Reply to the discussion on paper: 3-D numerical simulation of water flow over a broad-crested weir with openings by Daneshfaraz et al., 2019, in ISH journal of hydraulic engineering, DOI: 10.1080/09715010.2019. 1581098. ISH Journal of Hydraulic Engineering, 1-3, 2020.
  • [29] Ghaderi, A., Abbasi, S., Abraham, J., Azamathulla, H.M., Efficiency of trapezoidal labyrinth shaped stepped spillways. Flow Measurement and Instrumentation, 101711, 2020.
  • [30] Yakhot, V., Orszag, S.A., Thangam, S., Gatski, T.B., Speziale, C.G., Development of turbulence models for shear flows by a double expansion technique, Physics of Fluids A: Fluid Dynamics, Vol 4, No 7, 1510-1520, 1992.
  • [31] Crookston, BM., Labyrinth Weirs. PhD thesis, Utah State University, Logan, Utah, 2010.
  • [32] Indlekofer, H., Rouve, G., Discharge over polygonal weirs. ASCE, Journal of Hydraulic Engineering, Vol 101, No 3, 385- 401, 1995.