پیوندهای مفید
اخبار و اعلانات
آمار
| تعداد نشریات | 158 |
| تعداد شمارهها | 6,225 |
| تعداد مقالات | 67,685 |
| تعداد مشاهده مقاله | 114,922,961 |
| تعداد دریافت فایل اصل مقاله | 89,601,643 |
Scale Effects on the Discharge Coefficient of Ogee Spillway with an Arc in Plan and Converging Training Walls | ||
| Civil Engineering Infrastructures Journal | ||
| مقاله 11، دوره 49، شماره 2، اسفند 2016، صفحه 361-374 اصل مقاله (741.42 K) | ||
| نوع مقاله: Technical Notes | ||
| شناسه دیجیتال (DOI): 10.7508/ceij.2016.02.012 | ||
| نویسندگان | ||
| Mojtaba Saneie* 1؛ Jalal SheikhKazemi2؛ Mehdi Azhdary Moghaddam3 | ||
| 1Research Deputy of Soil Conservation and Watershed Management Research Institute | ||
| 2MSc. Hydraulic Structure Engineering, Faculty of Civil Engineering, University of Sistan & Baluchestan | ||
| 3Associate Prof., Faculty of Civil Engineering, University of Sistan & Baluchestan, Zahedan, Iran | ||
| چکیده | ||
| Dam spillways are the structures that lead rightly and safely the outflow downstream, so that the dam integrity can be guaranteed. Many accidents with dams have been caused by an inadequate spillway design or insufficient capacity. To accurately respond the hydraulic spillways, designers use physical modeling for designing this kind of structures. The scale effect in the spillway modeling, as a result, leads to the difference between the measured data and the prototype. In this study, an experimental model of Germi-Chay Mianeh dam spillway was made in three 1:100, 1:75, and 1:50 scales. Then, the water level in upstream of the spillway crest was measured in seven discharges and compared to 1:50 scale (basic scale), the percentage of water level difference on the crest was calculated in two physical models with 1:100 and 1:75 scales. Results revealed that as the scales of ogee spillway with an arc in plan and converging training walls decrease using Froude simulation, the effect of viscosity and surface tension increase in turn resulting in decreasing discharge coefficient. In this study, the scale effect in discharge coefficient ogee spillway was stated with K' equation. Using model family approved that the minimum Reynolds and Weber numbers which are 3.1×104 and 270, respectively indicated the minimum scale effect and thus, it is possible to avoid the effect of viscosity and surface tension in ogee spillway with an arc in plan and with converging training walls. Moreover, results obtained from the small scale which has been simulated using Froude simulation could be extrapolated to the prototype. | ||
| کلیدواژهها | ||
| Discharge coefficient؛ Ogee Spillway؛ Physical Modeling؛ Scale Effect؛ Surface Tension؛ viscosity | ||
| مراجع | ||
|
Boes, R.M. and Hager, W.H. (2003). “Two-phase flow characteristics of stepped spillways”, Journal of Hydraulic Engineering, ASCE, 129(9), 661-670. Boes, R.M. (2000). “Scale effects in modelling two-phase stepped spillway flow”, International Workshop on Hydraulics of Stepped Spillways, Balkema Publication, Zürich, Switzerland, pp. 53-60. Castro-Orgaz, O. and Hager, W.H. (2014). “Scale effects of round-crested weir flow”, Journal of Hydraulic Research, 52(5), 653-665. Chanson, H. and Chachereau, Y. (2013). “Scale effects affecting two phase flow properties in hydraulic jump with small inflow Froude number”, Experimental Thermal and Fluid Science, 45, 234-242. Chanson, H. (2008). “Physical modelling, scale effects and self-similarity of Stepped spillway flows”, World Environmental and Water Resources Congress Ahupua'a, ASCE. Chanson, H. (2004). “The hydraulics of open channel flow: An introduction”, Elsevier Butterworth-Heinemann, Burlington, MA, 2nd Edition, 253-274. Crookston, B.M. (2010). Labyrinth weirs, All Graduate Theses and Dissertations, Utah State University, paper 802. Mortensen, J.D., Barfuss, S.L. and Johnson, M.C. (2011). “Scale effects of air entrained by hydraulic jumps within closed conduits”, Journal of Hydraulic Research, 49(1), 90-95. Ettema, R., Arndt, R., Roberts, P. and Wahl, T. (2005). Hydraulic modeling: Concept and practice, Translated to Persian by Shamsaie, A. and Sarng, A., Sharif University of Technology, Institute of Scientific Publications, Tehran, Iran. EUA-Bureau of Reclamation. (1987). “Design of small dams”, 3rd Edition, Washington D.C., USA, 860 p. Erpicum, S., Tullis, B.P., Lodomez, M., Archambeau, P., Dewals, B.J. and Pirotton, M. (2016). “Scale effects in physical piano key weirs models”, Journal of Hydraulic Research, 54(6), 1-7. Fais, L.M.C.F. and Genovez, A.I.B. (2008). “Discharge rating curve and scale effects correction in Morning Glory Spillways”, Proceedings of 16th IAHR-APD Congress and 3rd Symposium of IAHR-ISHS, Hohai University, Nanjing, China, 2041-2046. Felder, S. and Chanson, H. (2009). “Turbulence dynamic similarity and scale effects in high-velocity free-surface flows above a stepped chute”, Experiments in Fluids, 47(1), 1-18. Felder, S. and Chanson, H. (2015). “Scale effects in high velocity air water flows on a stepped spillway”, 36th IAHR World Congress, The Hague, Netherlands, (27622770). Fox, R.W., McDonald, A.T., Pritchard and Philip J. (2011). Introduction to fluid mechanics, 19th Edition, Translated to Persian by Poosti, B., Academic Publishing, Tehran, Iran, 804 p. Ghodsian, M. (1998). “Viscosity and surface tension effects on rectangular weir flow”, International Journal of Engineering Science, Iran University of Science & Technology, 9(4), 111-117. Gonzalez, C.A. and Chanson, H. (2005). “Experimental study of turbulence manipulation in stepped spillway, Implications on flow resistance in skimming flows”, IAHR Congress, Seoul, Korea, pp. 2616-2626. Gonzalez, C.A. and Chanson, H. (2004). “Scale effects in moderate slope stepped spillways experimental studies in air-water flows”, The Institution of Engineers Australia, 8th National Conference on Hydraulics in Water Engineering, ANA Hotel Gold Coast, Australia. Heller, V. (2011). “Scale effects in physical hydraulic engineering models”, Journal of Hydraulic Research, 49(3), 293-306. Johnson, M.C. and Savage, B.M. (2006). “Physical and numerical comparison of flow over ogee spillway in the presence of tail water”, Journal of Hydraulic Engineering, ASCE, 132(12), 1353-1357. Murzyn, F. and Chanson, H. (2008). “Experimental assessment of scale effects affecting two-phase flow properties in hydraulic jumps”, Experiments in Fluids, 45(3), 513-521. Pfister, M., Battisacco, E., De Cesare, G. and Schleiss, A.J. (2013). “Scale effects related to the rating curve of cylindrically crested piano key weirs”, 2nd International Workshop on Labyrinth and Piano Key Weirs – PKW, Paris, France, pp. 73-82. Pfister, M., and Chanson, H. (2012). “Scale effects in physical hydraulic engineering models”, Journal of Hydraulic Research, 50(2), 244-246. Pfister, M. and Chanson, H. (2014). “Two phase air-water flows: Scale effects in physical modeling”, Journal of Hydrodynamics, 26(2), 291-298. Ranga Raju, K.G. and Asawa, G.L. (1977). “Viscosity and surface tension effects on weir flow”, Journal of the Hydraulics Division, ASCE, 103(10), 1227-1231. Wang, H. and Chanson, H. (2016). “Self-similarity and scale effects in physical modelling of hydraulic jump roller dynamics, air entrainment and turbulent scales”, Environmental Fluid Mechanics, 16(6), 1087-1110. | ||
|
آمار تعداد مشاهده مقاله: 1,595 تعداد دریافت فایل اصل مقاله: 1,639 |
||