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بررسی آزمایشگاهی اثر تخلخل و زاویه موانع نفوذپذیر بر رسوب‌گذاری جریان غلیظ | ||
| نشریه مهندسی عمران امیرکبیر | ||
| مقاله 10، دوره 52، شماره 6، شهریور 1399، صفحه 1455-1468 اصل مقاله (2.16 M) | ||
| نوع مقاله: مقاله پژوهشی | ||
| شناسه دیجیتال (DOI): 10.22060/ceej.2019.15394.5907 | ||
| نویسندگان | ||
| علیرضا جهانگیر1؛ کاظم اسماعیلی* 2؛ محمود فغفور مغربی3 | ||
| 1دانشگاه فردوسی مشهد | ||
| 2علوم ومهندسی آب/ دانشکده کشاورزی/ دانشگاه فردوسی مشهد | ||
| 3دانشکده مهندسی، گروه عمران، دانشگاه فردوسی مشهد | ||
| چکیده | ||
| جریان سیالبی رودخانه‌ها اغلب از نوع جریان غلیظ است. از این رو، شناخت و بررسی این جریان‌ها می‌تواند بخشی از مسائل رسوب‌گذاری را بر طرف نماید. در این پژوهش، اثر تخلخل و زاویه موانع نفوذپذیر بر کنترل و تله‌اندازی جریان غلیظ در آزمایشگاه بررسی شده است. برای این منظور، از یک پلیمر نامحلول و معلق ساخته شده از پلی استایرن انبساطی (EPS )با چگالی 1/135 گرم در لیتر و متوسط قطر 1/15 میلیمتر استفاده شد. موانع از صفحات پلاکسی گلاس انتخاب شدند که از دو نوع شیاری و حفرهای با عرض شیارها و قطر حفره‌هایی برابر با 3 میلیمتر ساخته شدند. آزمایش‌ها با دو غلظت متفاوت (10 و 20 درصد)، پنج تخلخل و چهار زاویه‌ی مختلف انجام شد. نتایج نشان دادند که با افزایش تخلخل، میزان تله‌اندازی تا تخلخل بهینه روند کاهشی و سپس افزایشی دارد. بر این اساس، تخلخل بهینه برای موانع حفرهای و موانع شیاری به ترتیب 22 و 19 درصد به دست آمد. در همه‌ی آزمایش‌ها، تله‌اندازی حفرهای، با 0/13 و 0/14 درصد به ترتیب در غلظت‌های ۱۰ و ۲۰ درصد، بیشتر از شیاری بود. علاوه بر این، با افزایش زاویه، مقدار تله‌اندازی کاهش یافت و مقدار آن در شیاری نسبت به حفرهای به ترتیب با ضریب همبستگی‌هایی برابر 0/961 و 0/937 ،بیشتر مشاهده شد. اثر عمده موانع، کاهش سرعت و ایجاد کندی جریان تشخیص داده شد که متوسط سرعت در حفرهای 3/62 درصد بیشتر از شیاری به دست آمد. بر مبنای نتیجه‌ها، در شرایط مشابه، همواره موانع حفرهای عملکرد بهتری از موانع شیاری دارند. | ||
| کلیدواژه‌ها | ||
| جریان غلیظ؛ رسوب‌گذاری معلق؛ زاویه نصب مانع؛ مانع نفوذپذیر؛ میزان تخلخل مانع | ||
| موضوعات | ||
| سازه های هیدرولیکی؛ محیط های متخلخل؛ هیدرولیک رسوب | ||
| عنوان مقاله [English] | ||
| Experimental Investigation Effect of the Porosity and Angle of Permeable Obstacles on Density Current Sedimentation | ||
| نویسندگان [English] | ||
| Alireza Jahangir1؛ kazem Esmaili2؛ Mahmoud Faghfour Maghrebi3 | ||
| 1Ferdowsi University of Mashhad | ||
| 2Head of dept. | ||
| 3Civil Engineering Department, Engineering Faculty, Ferdowsi University of Mashhad | ||
| چکیده [English] | ||
| Flood flow in rivers is often of density current type. Hence, recognizing and exploring these currents can solve some problems of sedimentation. In this study, the effect of porosity and the angle of permeable obstacles on the control and trapping of density current have been investigated in the laboratory. For this purpose, an expanded polystyrene (EPS) polymer was used with 1.135 g/L density and average diameter of 1.15 mm. The experiments were carried out with two concentrations (10 and 20%) and 5 porosity and 4 angles. The obstacles were made of palsy glass plates and two types of groove and cavity with 8.2 mm width of the groove and the diameter of the cavity. The results showed that, with an increase in porosity ratio, the amount of trapping to optimum porosity decreases and then increases. The optimal porosity of the cavity and groove is 22 % and 19%, respectively. In experiments, the cavity trapping was observed more than the groove, in the concentrations of 10.20% it was 0.13 and 0.14%, respectively. Also, with the increase of the angle, the amount of trapping has reduced and its value was observed in the groove more than the cavity. The correlation coefficient in the grooves and cavities was 0.996 and 0.937, respectively. The major effect of obstacles, reducing velocity and slowing flow were identified as the average velocity in the cavity was 3.62% higher than the groove. Accordingly, in the same conditions, the cavity obstacles have better performance than the groove obstacles. | ||
| کلیدواژه‌ها [English] | ||
| Density Current, Suspended Sedimentation, permeable Obstacle, Obstacle Angle, Obstacle porosity | ||
| مراجع | ||
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[1] Eghbalzadeh, M. Javan, Numerical simulation of a turbidity current flowing over a solid obstacle, in: 2nd International Conference on Environmental Science and Development, Singapore, 2011. [2] B.C. Kneller, Comments on the Origin and Significance of Density Stratification in Turbidity Currents, in: AGU Fall Meeting Abstracts, 2016. [3] S. Baghalian, M. Ghodsian, Experimental analysis and prediction of velocity profiles of turbidity current in a channel with abrupt slope using artificial neural network, Journal of the Brazilian Society of Mechanical Sciences and Engineering, 4517-4503 (2017) (11)39. [4] E. Meiburg, M.M. Nasr-Azadani, Gravity and Turbidity Currents: Numerical Simulations and Theoretical Models, in: Mixing and Dispersion in Flows Dominated by Rotation and Buoyancy, Springer, 2018, pp. 180-129. [5] N. Barahmand, A. Shamsai, Experimental and theoretical study of density jumps on smooth and rough beds, Lakes & Reservoirs: Research & Management, -285 (2010) (4)15 306. [6] P. Hu, Z. Cao, G. Pender, G. Tan, Numerical modelling of turbidity currents in the Xiaolangdi reservoir, Yellow River, China, Journal of hydrology, 53-41 (2012) 464. [7] I.Y. Vladimirov, N. Korchagin, A. Savin, Wave influence of a suspension-carrying current on an obstacle in the flow, in: Doklady Earth Sciences, Springer Science & Business Media, 2015, pp. 286. [8] A. Farizan, S. Yaghoubi, B. Firoozabadi, H. Afshin, Effect of an obstacle on the depositional behaviour of turbidity currents, Journal of Hydraulic Research, 89-75 (2019) (1)57. [9] S. Chamoun, G. De Cesare, A.J. Schleiss, Managing reservoir sedimentation by venting turbidity currents: A review, International Journal of Sediment Research, (3)31 204-195(2016). [10] S.A. Asghari Pari, S.M. Kashefipour, M. Ghomeshi, An experimental study to determine the obstacle height required for the control of subcritical and supercritical gravity currents, European Journal of Environmental and Civil Engineering, 1092-1080 (2017) (9)21. [11] S. Yaghoubi, H. Afshin, B. Firoozabadi, A. Farizan, Experimental investigation of the effect of inlet concentration on the behavior of turbidity currents in the presence of two consecutive obstacles, Journal of Waterway, Port, Coastal, and Ocean Engineering, (2)143 04016018 (2016). [12] S. Keshtkar, S.A. Ayyoubzaeh, M. Ghodsian, Changes in Turbidity Current Flow Velocity Due to the Obstacle Height and an Abrupt Decrease in a Reservoir Bed Slope, Water Enginnering, 69-55 (2017) (32)10. (In Persian) [13] G. De Cesare, C.D. Oehy, A.J. Schleiss, Experiments on turbidity currents influenced by solid and permeable obstacles and water jet screens, in: 6th International symposium on ultrasonic Doppler methods for fluid mechanics and fluid engineering, 2008, pp. 44-41. [14] S.A. Pari, S. Kashefipour, M. Ghomeshi, M.S. Bajestan, Effects of obstacle heights on controlling turbidity currents with different concentrations and discharges, Journal of Food, Agriculture & Environment, 935-930 (2010) (2)8. [15] C.D. Oehy, A.J. Schleiss, Control of turbidity currents in reservoirs by solid and permeable obstacles, Journal of Hydraulic Engineering, 648-637 (2007) (6)133. [16] M. Kordnaeij, S.A. Asghari Pari, S.M. Sajjadi, M. Shafai Bajestan, Laboratory Investigation the effect of porosity obstacle and stepped porosity obstacle on control of gravity current, Journal of Marine Science and Technology, (4)16 96-86 (2018). [17] S.A. Asghari Pari, S.M. Mohagheghiyan, Numerical Investigation Effect in Using Plate and Tilt Columnar Barrier in Controlling Turbidity Current, Iranian Journal of Irrigation & Drainage, 366-357 (2015) (2)9. [18] S.A. Asghari Pari, S. Yazdanfar, M. Kordnaeij, Numerical Investigating Effect of Obstacle’s Upstream Angle and Water Depth of Reservoir on Controlling Turbidity Current, Water and Soil Science, 219-207 (2016) (2-2)26. (In Persian) [19] M.A. Habib Mohammadi, S.A. Asghari Pari, S.M. Sajjadi, Experimental Investigation the Effects of Gabion Obstacle's Height, Shape and distance of obstacle from entrance to Control the Turbidity Current, Journal of Water and Soil Conservation, 265-251 (2016) (4)23. (In Persian) [20] E. Alves, R. Rossatto, Experimental study of turbidity currents flow around obstacles, in: 7th International Sympathy on Stratified Flows, Rome, Italy, 2011. [21] H. Nogueira, C. Adduce, E. Alves, M. Franca, The influence of bed roughness on the dynamics of gravity currents, in: River Flow - Murillo (Ed.), Taylor & Francis Group, London, 2012, pp. 362-357. [22] M. Janocko, M. Cartigny, W. Nemec, E. Hansen, Turbidity current hydraulics and sediment deposition in erodible sinuous channels: laboratory experiments and numerical simulations, Journal of Marine Petroleum Geology, 41 249-222 (2013). [23] J. McArthur, R. Wilson, H. Friedrich, Photometric analysis of the effect of substrates and obstacles on unconfined turbidity current flow propagation, in: Proc River Flow, 2014. [24] S. Yaghubi, P. Golchoubian, H. Afshin, B. Firoozabadi, Experimental Investigation of the Effect of Two Consecutive Obstacles on Turbidity Current, Journal of Selcuk University Natural and Applied Science, ((2013 627-615. [25] M. Zeynivand, S.M. kashefi Pour, M. Ghomeshi, Laboratory Investigation The Effect of Porosity of Permeable Obstacle on Control of Gravity Current, Irrigation Sciences and Engineering, 24-13 (2017) (1)40. [26] M.N. Abhari, M. Iranshahi, M. Ghodsian, B. Firoozabadi, Experimental study of obstacle effect on sediment transport of turbidity currents, Journal of Hydraulic Research, 629-618 (2018) (5)56. [27] R. Wilson, H. Friedrich, C. Stevens, Photometric velocity tracking tool for laboratory generated turbidity currents, in: River Flow 2016 – Constantinescu, Garcia & Hanes (Eds) Conference, 2016, pp. 867-862. [28] T. Tokyay, G. Constantinescu, E. Meiburg, Lockexchange gravity currents with a high volume of release propagating over a periodic array of obstacles, Journal of Fluid Mechanics, 605-570 (2011) 672. [29] T. Tokyay, G. Constantinescu, E. Gonzalez-Juez, E. Meiburg, Gravity currents propagating over periodic arrays of blunt obstacles: Effect of the obstacle size, Journal of Fluids and Structures, 806-798 (2011) (6-5)27. [30] M. Nasr-Azadani, E. Meiburg, Turbidity currents interacting with three-dimensional seafloor topography, Journal of Fluid Mechanics, 443-409 (2014) 745. | ||
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