مقایسه آبگذری سرریز کلیدپیانویی با سرریزهای اوجی و لبه تیز

نوع مقاله : پژوهشی اصیل (کامل)

نویسندگان
مسعود قدسیان 1
حسین سهراب زاده انزانی 2
1 دانشگاه صنعتی اصفهان
2 دانشگاه تربیت مدرس
10.22034/23.5.9
چکیده
یکی از مهم­ترین تأثیرات تغییرات آب و هوایی وقوع سیلاب­های ناگهانی است. ازآنجاکه حفظ سلامت سدها هنگام سیلاب ضروری می­باشد، لذا وجود سرریز مناسب در سدها امری غیرقابل‌انکار می­باشد. درواقع سرریزها وظیفه­ی انتقال آب از مخزن سد به پائین­دست را بر عهده دارند. در بین سرریزهای موجود، سرریز کلیدپیانویی جدیدترین سرریز می­باشد. هدف از مطالعه حاضر بررسی آبگذری سرریز کلیدپیانویی و مقایسه­ی آن با سرریز لبه­تیز و سرریز اوجی ­می­باشد. جهت بررسی این موضوع، آزمایش­ها در آزمایشگاه هیدرولیک دانشگاه تربیت مدرس تهران در فلومی به ابعاد ۱۰ ×۰٫۷۵×۰٫۹ متر بر روی سرریز کلیدپیانویی مستطیلی صورت گرفت. نتایج نشان داد متوسط ضریب آبگذری سرریز کلیدپیانویی ۰٫۴ و بیشترین میزان آن ۰٫۵۵ می­باشد که با افزایش بار آبی روی سرریز از مقدار آن کاسته شده و به مقدار ۰٫۳ میل می­کند. آبگذری سرریز کلیدپیانویی به‌طور متوسط ۲٫۵ برابر آبگذری سرریز اوجی می­باشد. این میزان برای آبگذری سرریز کلیدپیانویی نسبت به آبگذری سرریز اوجی ۳ می­باشد. محاسبات نشان داد متوسط استهلاک انرژی سرریز کلید­پیانویی نیز حدود ۰٫۳ می­باشد.

کلیدواژه‌ها

موضوعات

عنوان مقاله English

Comparison Df discharge Capacity of Piano Key Weir with Ogee And Sharp Crest Weirs

نویسندگان English

M. Ghodsian 1
H. Sohrabzadeh Anzani1 2
1 TMU
چکیده English

In this research, comparison of piano key weir with sharp crested weir and ogee spillway is addressed. The experimentally measured values of discharge of piano key weir were compared with their corresponding computed values for ogee spillway and sharp crested weir.

By using the dimensional analysis technique, dimensionless equation was obtained for discharge coefficient of rectangular piano key weir. Experiments were conducted in a rectangular channel with 10 m length, 0.75 m width and 0.9 m height. Experiments were conducted for various discharges and flow depths. All the experiments were conducted under free flow conditions at weir outlet. The discharge coefficients for the rectangular piano key weir were obtained based on the measured discharges and flow depth. The discharge of ogee spillway and sharp crested weir were estimated by using conventional weir equations.

The variations of discharge versus total upstream head showed almost linear increasing trend of discharge with total head. The plotted data showed a decreasing trend of discharge coefficient with increasing relative total head. The obtained discharge coefficients for the rectangular piano key weir varied between 0.3 and 0.55. The average discharge coefficient for this weir was 0.4.

At Ht/P = 0.28, the discharge through the rectangular piano key is almost 4 times the discharge of the ogee spillway. The average discharge of the piano key weir is about 2.5 times of the ogee spillway and about 3 times that of the sharp crest weir. The energy dissipation of the piano key weir is about 0.3.

According to the results, the piano key weir performs better than the ogee spillway and the sharp crest weir. Therefore, in the circumstances that the design discharge of the dams has increased due to climate changes, the piano key weir is a better alternative to ogee spillway, due to its higher efficiency.

کلیدواژه‌ها English

Ogee spillway
Sharp-crest weir
Piano key weir
Discharge coefficient
Hervouet JM., & Petitjean, A. 1999. "Malpasset dam-break revisited with twodimensional computations." Journal of hydraulic research 37(6): 777-788.
2. Aureli F., Maranzoni A., & Petaccia G. 2021. Review of Historical Dam-Break Events and Laboratory Tests on Real Topography for the Validation of Numerical Models. Water 13(14): 1968.
3. Muslu Y. 2001. Numerical analysis for lateral weir flow. Journal of Irrigation and Drainage Engineering 127(4): 246-253.
4. Machiels O. Erpicum S., Archambeau P., & Dewals, B. 2013. Parapet wall effect on piano key weir efficiency. Journal of Irrigation and Drainage Engineering 139(6): 506- 511.
5. Laugier F., Locgu A., Gille C., Leite Ribero M., & Boillat JL. 2009. Design and construction of a labyrinth PKW spillway at Saint-Marc dam, France. Hydropower & Dams 16(ARTICLE): 100-107.
6. Erpicum S. Tullis BP., Lodomez M., Archambeau P., Dewals BJ., & Pirotton M. 2016. Scale effects in physical piano key weirs models. Journal of Hydraulic Research, 54(6), 692-698.‏
7. 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.
8. Lempérière F., & Jun G. 2005. Low cost increase of dam’s storage and flood mitigation: the piano keys weir. Proc. of 19th Congress of ICID, Beijing, China.
9. Ouamane A., & Lempérière F., 2006. Design of a new economic shape of weir. Proceedings of the International Symposium on Dams in the Societies of the 21st Century, International Commission on Large Dams (ICOLD), Taylor and Francis. London.
10. Ribeiro ML., Bieri M., Boillat JL., Schleiss A., & Delorme F. 2009. Hydraulic capacity improvement of existing spillways–design of a piano key weirs. Proceedings (on CD) of the 23rd Congress of the Int. Commission on Large Dams CIGB-ICOLD.
11. Belaabed F., & Ouamane, A. 2011. Contribution to the study of the piano key weirs submerged by the downstream level. Labyrinth and Piano Key Weirs–PKW 2011: 89-96.
13. Anderson R.M., & Tullis B. 2012. Comparison of piano key and rectangular labyrinth weir hydraulics. Journal of Hydraulic Engineering 138(4): 358-361.
14. 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.
15. Belzner F., Merkel J., Gebhardt M., & Thorenz, C. 2017. Piano key and labyrinth weirs at German waterways: Recent and future research of the BAW.
16. Mehboudi A., Attari J., & Hosseini SA., 2017. Flow regimes over trapezoidal piano key weirs. Labyrinth and piano key weirs III–PKW 2017, CRC Press: 65-73.
17. Poshteh-Shirani M., Rahimpour M., & Ahmadi M.M. 2018. The Effect of upstream overhang on debris blocking and discharge capacity of piano Key weirs. Journal of Ferdowsi Civil Engineering 30(2). (In Persian)
18. Ghodsian M., & Sohrabzadeh Anzani H. 2022. Laboratory analysis of flow over rectangular piano key weir with slopped side walls. Modares Civil Eng. Journal of Nov 5. (In Persian)
19. Sohrabzadeh Anzani H., & Ghodsian M. 2022. Experimental study of the effect of sidewall slope over the triangular PK weir. Journal of Hydraulics. 17.(4): 17-30.‏ https://doi.org/10.30482/jhyd.2022.326177.1581
20. Sohrabzadeh Anzani H., & Ghodsian M. 2023. Laboratory investigation of the discharge coefficient of the rectangular piano key weir with a discontinuous sloping crest. Journal of Hydraulics.
21. Sohrabzadeh Anzani H., & Ghodsian, M. 2023. Energy dissipation of triangular piano key weir. Journal of Hydraulics. http:// doi.org/10.30482/JHYD.2023.365692.1622
22. Ribeiro ML., Pfister M., & Schleiss AJ. 2013. Overview of Piano Key weir prototypes and scientific model investigations. Proceedings of the 2nd International Workshop on Labyrinth and Piano Key Weirs.
23. Pfister M., Battisacco E., De Cesare, G. & Schleiss, AJ. 2013. Scale effects related to the rating curve of cylindrically crested Piano Key weirs. In Labyrinth and Piano Key Weirs II—PKW 2013; CRC press: Paris, France, pp. 73–82.
24. Anderson RM. & Tullis BP. 2013 Piano Key Hydraulics and Labyrinth Weir Comparisons. Journal of Irrigation and Drainage Engineering (ASCE), 139, 246-253. http://dx.doi.org/10.1061/(ASCE)IR.1943-4774.0000530.
25. Ribeiro M.L., Pfister M., Schleiss AJ., & Boillat JL. 2012. Hydraulic design of A-type piano key weirs. Journal of Hydraulic Research, 50(4), 400-408.‏
26. Hager W.H., & Schleiss A.J. 2009. Constructions hydrauliques, ecoulements stationeries (Hydraulic structures, steady flow). Traité de Génie Civil. Presses Polytechniques et Universitaires Romandes, Lausanne, Switzerland.
27. Tullis JP., Amanian N., & Waldron D. 1995. Design of labyrinth spillways. Journal of hydraulic engineering, 121(3), 247-255.‏
28. Eslinger K., & Crookston BM. (2020). Energy dissipation of type a piano key weirs. Water. Apr 28;12(5):1253.
مهندسی عمران مدرس
دوره 23، شماره 5
مهر و آبان 1402
صفحه 129-138