بررسی عددی جریان و ضریب دبی جریان بر روی سرریزهای نوک اردکی و مایل

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشجوی دکتری سازه‌های آبی، دانشکده کشاورزی، دانشگاه تبریز.

2 استادیار سازه‌های آبی، دانشکده کشاورزی، دانشگاه تبریز.

چکیده

در یک عرض مشخص سرریزهای نوک‌اردکی و مایل دارای طول مؤثر بیش‌تری می‌باشندکه این مسئله می‌تواند بر ضریب دبی و راندمان این نوع سرریزها تأثیرگذار باشد. در این تحقیق، تلاش شد تا نقش برخی از پارامترهای هیدرولیکی و هندسی سرریزهای ذکر شده و ارتفاع آن‌ها بر روی ضریب دبی جریان در داخل کانال با استفاده از مدل عددی فلوئنت مورد بررسی قرار‌ گیرد و نتایج حاصل از این مدل با نتایج مدل Flow-3D و اطلاعات آزمایشگاهی مقایسه شود. فشار، سرعت و سطح آزاد جریان با استفاده از مدل آشفتگی RNG ɛk- و مدل چند فازی (VOF) با حل عددی تعیین گردیدند. معیار نرمال میانگین مجذور مربعات خطا (RMSE) مدل فلوئنت در شبیه‌سازی ضریب دبی جریان 0565/0 به‌دست آمد که نشان‌دهنده دقت بالای این مدل می‌باشد. بررسی نتایج حاصله نشان می‌دهد که در هر دو سرریز، ضریب دبی با افزایش انرژی بالادست سرریز (Hd)، کاهش می‌یابد. حداکثر مقدار ضریب دبی در محدوده 35/0≥ (Hd/P) در هر دو سرریز نوک‌اردکی و مایل مشاهده شد. نتایج حاکی از آن بود که سرریزهای مایل در مقایسه با سرریزهای نوک‌اردکی دارای ضریب دبی بیشتری بوده (5/0 برابر ضریب دبی سرریزهای نوک‌اردکی) و در نتیجه از ظرفیت دبی عبوری (افزایش 33 درصدی) بالاتری نسبت به سرریزهای نوک‌اردکی برخوردار می‌باشند.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Numerical Investigating of Flow and Discharge Coefficient Over the Duckbill and Oblique Weirs

نویسندگان [English]

  • Somayeh Emami 1
  • Javad Parsa 2
1 Ph.D. student of Water Structures, Department of Water Engineering, Faculty of Agriculture, Tabriz University, Tabriz, Iran.
2 Assistant Professor of Water Structures, Department of Water Engineering, Faculty of Agriculture, Tabriz University, Tabriz, Iran.
چکیده [English]

For a given channel width, duckbill and oblique weirs have longer effective length, and this could be effective on their dis-charge coefficients and efficiency. In this study, we tried to examine the role of some of the hydraulic and geometric parameters of mentioned weirs and their height on the discharge coefficient into the channel using the Fluent numerical model and the results of this model compared with the Flow-3D model and experiments data. The pressure, velocity, turbulence, and the free surface of the flow were modeled by k-ε RNG and volume of fluid (VOF) algorithms, respectively. The NRMSE of the Flu-ent model in the simulation of the discharge coefficient was 0.0565, which indicates the high accuracy of the model. Results showed that in both weirs, the discharge coefficient decreases with increasing discharge or upstream head. The maximum dis-charge coefficient was found in the H/P≤ 0.35 in both weirs. The results indicated the oblique weirs had a higher discharge coefficient compared with duckbill weirs and thus had higher flow capacity.

کلیدواژه‌ها [English]

  • Discharge Coefficient
  • Duckbill Weir
  • Oblique weir
  • Turbulence Model
  • Volume of Fluid
[1] Bos, M. G. (1988). “Discharge measurement structures”, International Institute for Land Reclamation and Improvement (ILRI).

[2] Beyrami, M.K. (2009). “Water Transfer Structures”, Isfahan University of Technology Publications.

[3] BeihaghiKondari, A., Zeiae, N. A., khodashenas, R. S., & Zahedi, H. (2012). “Simulation lateral weirs in rec-tangular canal using Fluent software”, 9th international civil engineering congress, 19-21 Ordibehesht, Esfahan University.

[4] Zahiri, A. (2014). “Extracting the relationship between the discharge coefficient in arc weirs by genetic plan-ning”, Irrigation and drainage, 9(2), 232-244.

[5] Nikpeik, P., Kashefipour, S. M., & Mpltaji, A. (2011). “Investigation on the effect of duckbill weir geometry on discharge coefficient”, Chaloos Islamic University Pub. Chaloos, Iran, 39(1), 1-10.

[6] Saiedi, M., Shaghaghian, M. R., & Zayeri, M. R. (2014). “Investigation of flow pattern on duckbill weir using Flow-3D Model”, Second national conference on applied research in civil, architecture and urban manage-ment.

[7] Emami, S. (2016).“Numerical investigation of geometric parameters effect of the duckbill weir on the dis-charge coefficient”, M.Sc. Thesis of Hydraulic Structures, Department of Water Engineering, University of Ta-briz.

[8] Haghiabi, H., Abbaspour, B., Maleki, A., & TorabiPoudeh, H. (2015). “Simulation of flow pattern on hori-zontal triangular weirs and comparison with linear weirs using Flow-3D model”, Journal of Water Engineering, 9, 125-137.

[9] Azhdari-Moghaddam, M., Amanian, N. A., & JafariNadoshan, A. (2011). “Investigation the lenghth and angle of the head of the trapezoid labyrinth weir using CGD”, 6th national civil engineering congress, 6-7 May, Semnan University.

[10] Tingey, S. E. (2011). “Discharge coefficient of oblique weirs”, M. Sc. Thesis in Mechanical Engineering, Utah State University, USA, 51 p.

[11] Noori, B. M. A., & Chilmeran, T. A. H. (2005). “Characteristics of flow over normal and oblique weirs with semicircular crests”, Al_Rafidain Engineering, Journal, 13(1), 49-61.

[12] Rezaee, M., Emadi, A., & Aqajani Mazandarani, Q. (2015). “Experimental Study of Rectangular Laby-rinth Weir”, Journal of Water and Soil, 29(6), 1438-1446.

[13] Khode B. V., Tembhurkar A.R., Porey P. D., & Ingle R. N. (2012). “Experimental studies on flow over laby-rinth weir”, Journal of Irrigation and Drainage Engineering,10, (ASCE) IR.21p.

[14] Anees, K. I., Riyadh, A. l. A., LioydH, C., Chua, A., & Subrat, D. (2016). “Determination of discharge coef-ficient for flow over one cycle compound trapezoidal plan form labyrinth weir”, International Journal of Civil Engineering and Technology, 7(4), 314-328.

[15] Hirt, C. W., & Nichols, B. D. (1981). “Volume of fluid (VOF) method for the dynamics of free boundaries”, Journal of Computational Physics, 39, 201-225.

[16] Borghei, S. M., Vatannia, Z., Ghodsian, M., & Jalili Ghazizadeh, M. R. (2003). “Oblique rectangular sharp-crested weir”, Proceedings of the Institution of Civil Engineers, Water and Maritime Engineering, 156(2), 185-191.

[1] Bos, M. G. (1988). “Discharge measurement structures”, International Institute for Land Reclamation and Improvement (ILRI).

[2] Beyrami, M.K. (2009). “Water Transfer Structures”, Isfahan University of Technology Publications.

[3] BeihaghiKondari, A., Zeiae, N. A., khodashenas, R. S., & Zahedi, H. (2012). “Simulation lateral weirs in rectangular canal using Fluent software”, 9th international civil engineering congress, 19-21 Ordibehesht, Esfahan University. 

[4] Zahiri, A. (2014). “Extracting the relationship between the discharge coefficient in arc weirs by genetic planning”, Irrigation and drainage, 9(2), 232-244.

[5] Nikpeik, P., Kashefipour, S. M., & Mpltaji, A. (2011). “Investigation on the effect of duckbill weir geometry on discharge coefficient”,Chaloos Islamic University Pub. Chaloos, Iran, 39(1), 1-10.

[6] Saiedi, M., Shaghaghian, M. R., & Zayeri, M. R. (2014). Investigation of flow pattern on duckbill weir using Flow-3D Model, Second national conference on applied research in civil, architecture and urban management.

[7] Emami, S. (2016).“Numerical investigation of geometric parameters effect of the duckbill weir on the discharge coefficient”, M.Sc. Thesis of Hydraulic Structures, Department of Water Engineering, University of Tabriz.

[8] Haghiabi, H., Abbaspour, B., Maleki, A., & TorabiPoudeh, H. (2015). Simulation of flow pattern on horizontal triangular weirs and comparison with linear weirs using Flow-3D model, Journal of Water Engineering, 9, 125-137.

[9] Azhdari-Moghaddam, M., Amanian, N. A., & JafariNadoshan, A. (2011). “Investigation the lenghth and angle of the head of the trapezoid labyrinth weir using CGD”, 6th national civil engineering congress, 6-7 May, Semnan University. 

[10] Tingey, S. E. (2011). “Discharge coefficient of oblique weirs”, M. Sc. Thesis in Mechanical Engineering, Utah State University, USA, 51 p. 

[11] Noori, B. M. A., & Chilmeran, T. A. H. (2005). “Characteristics of flow over normal and oblique weirs with semicircular crests”, Al_Rafidain Engineering, Journal, 13(1), 49-61.

[12] Rezaee, M., Emadi, A., & Aqajani Mazandarani, Q. (2015). “Experimental Study of Rectangular Labyrinth Weir”, Journal of Water and Soil, 29(6), 1438-1446.

[13] Khode B. V., Tembhurkar A.R., Porey P. D., & Ingle R. N. (2012). “Experimental studies on flow over labyrinth weir”, Journal of Irrigation and Drainage Engineering,10, (ASCE) IR.21p.

[14] Anees, K. I., Riyadh, A. l. A., LioydH, C., Chua, A., & Subrat, D. (2016). “Determination of discharge coefficient for flow over one cycle compound trapezoidal plan form labyrinth weir”, International Journal of Civil Engineering and Technology, 7(4), 314-328. 

[15] Hirt, C. W., & Nichols, B. D. (1981). “Volume of fluid (VOF) method for the dynamics of free boundaries”, Journal of Computational Physics, 39, 201-225.

[16] Borghei, S. M., Vatannia, Z., Ghodsian, M., &  Jalili Ghazizadeh, M. R. (2003). “Oblique rectangular sharp-crested weir”, Proceedings of the Institution of Civil Engineers, Water and Maritime Engineering, 156(2), 185-191.

 

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