Analysis of stage-discharge theoretical and laboratory relationships in morning glory sharp crested weir

Document Type : Original Article

Authors

1 Razi University

2 department of water engineering, razi university

Abstract

In this study, a special type of sharp-crested weir is called sharp- crested morning glory weir (SCMGW) is introduced. Due to the special shape of this weir, high measurement accuracy in low discharge, and in flood and sudden discharges, less back water profile is expected upstream. On the other hand, there is no discontinuity in their stage-discharge relationship. Assuming the occurrence of a critical flow in the weir crest, the general stage-discharge relationship was extracted for this type of weir. The next step was to correct this assumption, considering that the assumption of the occurrence of a critical flow in the weir crest is accompanied by an error, and consequently the stage-discharge relationship obtained based on this assumption is not accurate. For this purpose, by measuring 57 experiments on 5 types of this weir, the stage-discharge relationship was extracted and it was shown that for a specific stage, the measured flow is greater than the calculated analytical flow. A correction coefficient was applied to the analytical relation with the aim of matching the stage-discharge analytic relationship with the measurement. This correction factor was optimized and extracted using the gene expression programming method as a function of the weir height-to-head ratio (p / H) and the a / n ratio (a and n parameters of the weir geometric shape). The results showed that the modified discharge-stage relationship estimated the measured discharge values as R2 = 0.98, mean absolute error MAE = 0.442 liters and root mean square error of RMSE = 0.08 liters.

Keywords

References

Akhbari, A., Zaji, A. H., Azimi, H. and M. Vafaeifard. 2017. Predicting the discharge coefficient of triangular plan form weirs using radian basis function and M5’ methods. Journal of Applied Research in Water and Wastewater. 4 (1): 281-289
Ayaz, Md. and Mansoor, T. 2018. Discharge coefficient of oblique sharp crested weir for free and submerged flow using trained ANN model. Water Science. 32(2): 192-212.
Aydin, I., Altan-Sakarya, A. B., and Sisman, C. 2011. Discharge formula for rectangular sharp-crested weirs. Flow Measurement and Instrumentation 22(2): 144-151.
Bagheri, S. and Heidarpour, M. 2010. Flow over rectangular sharp-crested weirs. Irrigation science. 28(2): 173-179. ‏
Bahman, E., and Kabiri-Samani, A. 2021. Experimental investigation of flow characteristics over asymmetric Joukowsky hydrofoil weirs for free and submerged flow. Flow Measurement and Instrumentation, 79, 101938. ‏
Bautista-Capetillo, C., Robles, O., Júnez-Ferreira, H., and Playán, E. 2014. Discharge coefficient analysis for triangular sharp-crested weirs using low-speed photographic technique. Journal of Irrigation and Drainage Engineering. 140(3): 06013005.
Bos, M.G.1989.Discharge Measurement Structures. International Institute for Land Reclamation and Improvement (ILRI), Publication 20, Wageningen, Netherlands.
Castro-Orgaz, O., Giráldez, J. V. and. Ayuso, J. L. 2008. Critical flow over circular crested weirs. Journal of Hydraulic Engineering 134(11): 1661-1664.
Ferreira, C. 2002. Gene expression programming in problem solving. In soft computing and industry (pp. 635-653). Springer, London. ‏
Ghobadian, R. and E. Meratifashi، E. 2012. Modified theoretical stage-discharge relation for circular sharp-crested weirs. Water Science and Engineering. 5(1): 26-33
Gong, J., Deng, J. and Wei, W. 2019. Discharge coefficient of a round-crested weir. Water, 11(6):1206. ‏
Igathinathane, C., Srikanth, I., Prakash, K., Ramesh, B., and A. R. Womac. 2007. Development of parabolic weirs for simplified discharge measurement. Biosystems engineering. 96(1): 111-119.
Ionescu, C. S., Nistoran, D. E. G., OPRIŞ, I. and SIMIONESCU, Ș. M. 2019. Sensitivity Analysis of Sharp-Crested Weirs as a Function of Shape Opening, for Small Discharges. Hidraulica. 2: 43-51. ‏
Kumar, S., Ahmad, Z., and Mansoor, T. 2011. A new approach to improve the discharging capacity of sharp-crested triangular plan form weirs. Flow Measurement and Instrumentation. 22(3): 175-180.
Liong, S.Y., Gautam, T.R., Khu, S.T., Babovic, V., Keijzer, M. and Muttil, N. 2002. Genetic programming: A new paradigm in rainfall runoff modeling.     Journal of American Water Resources Association. 38 (3): 705-718.
Lopes, H.S. and Weinert, W.R. 2004. EGIPSYS: An enhanced gene expression     programming approach for symbolic regression problems. International Journal of Applied Mathematics and Computer Science. 14(3): 375-384.
 Martinez R.E., Reca J., Morillas M.T. and Lopez, J.G. 2005. Design and calibration of compound sharp crested weir. Journal of Hydraulic Engineering. ASCE. 131 (2):112- 116
Parsaie, A. and Haghiabi, A. H. 2021. Uncertainty analysis of discharge coefficient of circular crested weirs. Applied Water Science. 11(2): 1-6.
Ramamurthy, A. S., Tim, U. S., and Rao, M. V. J. 1987. Flow over sharp-crested plate weirs. Journal of irrigation and drainage Engineering, 113(2): 163-172. ‏
Ranga Raju, K. and Asawa, G. 1977. Viscosity and surface tension effects on weir flow. Journal of the Hydraulics Division. 103(HY10): 1227-1231.
Salehi, S., Esmaili, K. and Azimi, A. H. 2019. Mean velocity and turbulent characteristics of flow over half-cycle cosine sharp-crested weirs. Flow Measurement and Instrumentation. 66: 99-110.
Saneie, M., SheikhKazemi, J. and Azhdary Moghaddam, M. 2016. Scale effects on the discharge coefficient of ogee spillway with an arc in plan and converging training walls. Civil Engineering Infrastructures Journal. 49(2): 361-374.
Thornton, C. I., Meneghetti, A. M., Collins, K., Abt, S. R. and Scurlock, S. M. 2011. Stage‐Discharge Relationships for U‐, A‐, and W‐Weirs in Un‐Submerged Flow Conditions. Journal of the American Water Resources Association. 47(1): 169-178. ‏
Zachoval Z., Knéblová M., Roušar L., Rumann J. and Šulc, J. 2014. Discharge coefficient of rectangular sharp-edged broad-crested weir. Journal of Hydrolpgy Hydromech. 62(2): 145–149.
Iranian Journal of Irrigation & Drainage
Volume 16, Issue 4 - Serial Number 94
September and October 2022
Pages 762-776

Files

Share

How to cite

Statistics