Arman Guilaninezhad - Department of Civil Engineering, Tonekabon Branch, Islamic Azad University, Tonekabon, Iran.
Adeleh Saedi - Department of Civil Engineering, Tonekabon Branch, Islamic Azad University, Tonekabon, Iran.
Mehdi Nezhadnaderi - Department of Civil Engineering, Tonekabon Branch, Islamic Azad University, Tonekabon, Iran.

One of the effective methods for protecting the shores of navigable rivers at the site of the arches is submerged vanes. In order to study a case in the Netherlands, a numerical study was carried out on the effects of using submerged vanes on the protection of the coast in the Netherlands. In the present study, the numerical results of the impact of a submerged vane at a distance of one fourth of the width of the internal and external arc with a full arc length of ۹۰ degrees are paid to the average velocity distribution and pressure in the arc of ۹۰ degrees, with a width of ۳۵۰ meters and a depth of ۴.۵ meters. The results of the study showed that the presence of a submerged vane close to the inner arch, about one quarter of the width of the internal arc produces a counterflow stream that reduces the normal secondary flow in the bends of the river.Hence, the high- velocity current, which is driven radially to the inner shore, is diverted to the middle direction. So it will improve the sedimentation on the inner shore of the bend and scouring on the outer shore of the bend. In this way, the flow rate from the mean value of one meter per second reaches ۱.۹۸ m/s in the middle region and decreases from the sedimentation in this range

submerged vanes, Flow pattern, Secondary currents, ۹۰ Degree bend, Coast protection.