The effects of constructing Groynes to protect the coasts of the Dehnehsar Sefidroud area

With the increase in construction in the sea, the use of protective structures to prevent their instability in the marine environment is of environmental concern. Coastal protection structures are used in marine structural engineering to reduce flow turbulence around marine structures to prevent scouring. In this research, the flow simulation around breakwaters constructed in the Dehnehsar Sefidroud area located in Guilan province was investigated using computational fluid dynamics and Fluent software. By constructing the breakwater structure, the speed between the breakwaters is reduced and conditions for sediment accumulation are provided. Also, the negative pressure on the west side of the western breakwater is reduced and reaches a positive value, changing from erosion potential to sedimentation potential. There is negative pressure in a part of the western tip of the breakwater, which will cause local scouring and needs protection. The results of the ۲D and ۳D models of isovelocity vectors with the installation of breakwaters of ۹۰, ۹۴ and ۵۵ meters in length on the shore of the mouth of the Sefidrud River show that the velocity in the space between the ۹۰, ۹۴ and ۵۵ meter breakwaters decreases, reducing the risk of scouring and allowing sediments that move west to east on the shore to accumulate. Also, the results of isovelocity vectors and contours show that with the installation of breakwaters implemented on the shore of the mouth of the Sefidrud River, the pressure in the space between the ۹۴ and ۵۵ meter breakwaters decreases, reducing the risk of scouring.

Keywords:

Groyne , Flow Pattern , Erosion , Computational Fluid Dynamics , Sefidroud mouth