@article { author = {Karimi, S. and Zarrati, A. R.}, title = {Numerical Simulation of Bridge Contraction Scouring at Abutments}, journal = {Journal of Hydraulics}, volume = {8}, number = {2}, pages = {75-88}, year = {2013}, publisher = {Iranian Hydraulic Association}, issn = {2345-4237}, eissn = {2645-8063}, doi = {10.30482/jhyd.2014.7465}, abstract = {With the increasing progress in computer calculation speed, the 3D simulation of flow together with sediment transport has become possible. In the present work 3D numerical modeling of flow pattern and scouring around bridge abutments is conducted.  For this purpose the SSIIM model was utilized. In the first stage of calculation flow around an abutment on a non erodible bed was modeled and results were compared with the experimental data. The results showed a good agreement for the velocity field and water surface level. It was also concluded that the difference between the numerical results and experimental measurements increased as the abutment length or flow discharge or in another word flow disturbance and turbulence increased. The numerical model was then used for scour prediction around the abutment. Results showed a good agreement with experimental data for the location of the maximum scour depth. However, the scour depth was under predicted by 16%. The present study shows the validation and errors of such models for application in river engineering problems.}, keywords = {3D numerical model,contraction,Bridge abutment,Sediment transport,Scouring}, title_fa = {ﻣﺪل‌ﺳﺎزی ﻋﺪدی آبﺷﺴﺘﮕﯽ در ﻣﺤﻞ ﺗﻨﮓﺷﺪﮔﯽ ﮐﻮﻟﻪ ﭘﻞ}, abstract_fa = {ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﭘﯿﺸﺮﻓﺖ روز اﻓﺰون ﻗﺪرت راﯾﺎﻧﻪﻫﺎ و ﺗﻮﺳﻌﻪ ﻣﺪلﻫﺎی ﻋﺪدی ﺗﻮاﻧﻤﻨﺪ ﮐﻪ ﻗﺎدر ﺑﻪ ﺷﺒﯿﻪﺳﺎزی ﺟﺮﯾﺎن و اﻧﺘﻘﺎل ‫رﺳﻮب ﺑﻪ ﺻﻮرت ﺳﻪ‌بعدی ﻣﯽﺑﺎﺷﻨﺪ، اﻓﻖ ﺟﺪﯾﺪی در ﻧﺤﻮه ﻣﺤﺎﺳﺒﺎت ﺑﺮای ﻣﻬﻨﺪﺳان ﮔﺸﻮده ﺷـﺪه اﺳـﺖ. ﻫﺪف اﯾﻦ ﻣﻘﺎﻟﻪ ﻣﺪل‌ﺳﺎزی ﻋﺪدی ﺳﻪ‌بعدی ﺟﺮﯾﺎن و رﺳﻮب در ﻣﺤﻞ ﺗﻨﮓﺷﺪﮔﯽ ﯾﮏ ﭘـﻞ ﺑـﻪ ﻣﻨﻈـﻮر ﻣﺤﺎﺳـﺒﻪ آبﺷﺴـﺘﮕﯽ در ‫اﻃﺮاف ﮐﻮﻟﻪﻫﺎ ﻣﯽﺑﺎﺷﺪ. ﺑﺮای اﯾﻦ ﻣﻨﻈﻮر ﺑﻪ دﻟﯿﻞ ﻗﺎﺑﻠﯿﺖﻫﺎی زﯾﺎد ﻣﺪل ﻋﺪدی SSIIM2، اﯾﻦ ﻣﺪل اﻧﺘﺨﺎب و از آن اﺳﺘﻔﺎده ﺷﺪه اﺳﺖ. در ‫ﺗﺤﻘﯿﻖ ﺣﺎﺿﺮ، اﯾﻦ ﻣﺪل در ﺷﺒﯿﻪﺳﺎزی ﺗﻨﮓﺷﺪﮔﯽ در اﺛﺮ ﻗﺮارﮔﯿﺮی ﮐﻮﻟﻪ ﭘﻞ در ﺑﺴﺘﺮ ﺻﻠﺐ و ﻓﺮﺳﺎﯾﺶﭘﺬﯾﺮ ﺑﮑﺎر ﮔﺮﻓﺘﻪ ﺷـﺪه و ﺑـﺎ ‫ﻧﺘﺎﯾﺞ آزﻣﺎﯾﺸﮕﺎﻫﯽ ﻣﻘﺎﯾﺴﻪ شده اﺳﺖ. نتایج نشان داد دقت مدل عددی در پیش بینی تراز سطح آب و توزیع سرعت خوب است، ولی هر مقدار اختلال در جریان اطراف کوله به علت بالارفتن دبی یا افزایش طول کوله زیاد شود، خطای مدل عددی نیز افزایش می‌یابد. مدل عددی برای ﺗﻐﯿﯿـﺮات ﺑﺴـﺘﺮ و ‫ﻋﻤﻖ آبﺷﺴﺘﮕﯽ اطراف کوله نیز بررسی شد و نتایج نشان داد ﻣﺪل عددی ﺗﻐﯿﯿﺮات ﺑﺴﺘﺮ را در ﻣﻘﺎﯾﺴﻪ ﺑﺎ ﻣﺪل آزﻣﺎﯾﺸﮕﺎﻫﯽ ﺑﻪ ﺧﻮﺑﯽ پیش‌بینی کرده و ﻣﺤﻞ ﺣﺪاﮐﺜﺮ ﻋﻤﻖ آبشستگی را به درستی ﺗﻌﯿﯿﻦ ﻣﯽﮐﻨﺪ. وﻟﯽ ﻋﻤﻖ ﺣﻔﺮه آبشستگی در مسأله مورد بررسی در ﺣﺪود 16% از ﻧﺘﺎﯾﺞ آزﻣﺎﯾﺸﮕﺎﻫﯽ کمتر بدست آمد. ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﻧﺘﺎﯾﺞ ﺣﺎﺻله، دﻗـﺖ ﻣـﺪل ﻋـﺪدی ﻣـﺬﮐﻮر ﺑـﺮای ﻣﺪل‌ﺳﺎزی ‫ﺗﻨﮓﺷﺪﮔﯽ ﺑﻪ ﻋﻨﻮان ﯾﮑﯽ از ﻣﺴﺎﺋﻞ ﻣﻬﻨﺪﺳﯽ رودﺧﺎﻧﻪ ﻣﺸﺨﺺ ﺷﺪه اﺳﺖ.}, keywords_fa = {ﻣﺪل‌ﺳﺎزی ﻋﺪدی ﺳﻪ‌بعدی,ﺗﻨﮓﺷﺪﮔﯽ,ﮐﻮﻟﻪﭘﻞ,اﻧﺘﻘﺎل رﺳﻮب,آبشستگی.‬‬‬‬‬‬‬‬‬‬‬‬‬‬}, url = {https://jhyd.iha.ir/article_7465.html}, eprint = {https://jhyd.iha.ir/article_7465_bc85e93197da4badc2ed4f38beb82ff8.pdf} }