Investigating the impact of the vortex breaker on the hydraulics of the flow (empirical hydraulic coefficient ) passing over the morning glory spillway

In recent decades, many dams have been built. Due to the high need for water and the increasing soil erosion in different areas, the need to build a dam is quite obvious. In ۱۹۰۰, the number of large dams did not exceed ۵۰. However, between ۱۹۵۰ and ۱۹۸۶, the number of large dams (more than ۱۵ meters high) was more than ۳۹,۰۰۰. Since the ۷۰s, the construction of dams has been developing more and more. This expansion has been more visible in the Asian, Central and South American regions. According to the construction purpose, each dam structure must be able to pass the volume of excess water caused by the flood, and for this purpose, various structures such as spillways are used. The spillways are different according to the type of exploitation and the type of project. In other words, there are different types of leaks. Which are one of these types of shaft spillway. The spillway of a morning glory consists of a circular crest that directs the flow to an inclined or vertical axis. The mentioned axis is connected to a conduct way with a low gradient. In this research, in order to investigate the performance of both vortex breakers on the hydraulic spillway of morning glory, several tests have been conducted with various types of vortex breakers. The results show that the best vorticity channel with a low height and length is an arrangement of ۶, which increases the flow rate by ۲۳%. It should be noted that increasing the thickness of the vortex breaker by more than ۷% of the spillway radius does not have much effect on the increase of the spillway coefficient.