| فنی،مدیریتی،حقوقی| اعتبار،چابکی،پاسخگویی|
نوع مقاله : مقاله پژوهشی
نویسندگان
1 کارشناسی ارشد عمران-آب و سازههای هیدرولیکی دانشگاه علم و فرهنگ، تهران، ایران
2 استادیار، پژوهشکده حفاظت خاک و آبخیزداری، سازمان تحقیقات، آموزش و ترویج کشاورزی، تهران، ایران
3 کارشناسی ارشد عمران-آب و سازههای هیدرولیکی، دانشگاه علم و فرهنگ، تهران، ایران
کلیدواژهها
عنوان مقاله English
نویسندگان English
This study numerically investigates the effect of channel bend radius on the performance of 25% permeable spur dikes series in controlling the flow pattern. Two outer bends of a meandering channel with radii of 3.5 m and 4.5 m are simulated and compared under a constant discharge of 40 L/s. The two dimensional flow field is modeled using HEC RAS 2D, and spur dikes with four geometric configurations (T shaped, L shaped, inverted L, and straight I) are installed in series along each bend.
The comparison indicators include velocity distribution along the outer bend, streamline patterns, and the reduction of mean velocity relative to the no spur dikes (reference) condition. The results show that reducing the bend radius from 4.5 m to 3.5 m, while keeping the discharge constant at 40 L/s, intensifies the curvature effect and concentrates more flow towards the outer bank. Consequently, the role of spur dikes in reducing velocity near the outer bend becomes more pronounced. Specifically, for the 3.5 m radius, the reduction in mean velocity within the outer bank region is greater than that of the 4.5 m radius for all spur dikes geometries. The T shaped spur dikes exhibits the best performance in both radii, but its effect is more significant in the 3.5 m bend.
Overall, the findings indicate that in bends with smaller radii, properly designed permeable spur dikes can more effectively mitigate outer bank erosion and should be carefully considered in the design of bank protection systems
کلیدواژهها English
