نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی سابق کارشناس ارشد آبیاری و زهکشی بخش آب دانشکده کشاورزی، دانشگاه شیراز
2 دانشیار بخش آب، دانشکده کشاورزی، دانشگاه شیراز
3 استادیار گروه مهندسی آب، دانشکده کشاورزی، دانشگاه شهرکرد
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
Study on the reduction of flow energy intensity in order to reduce damage of the downstream hydraulic structures, always has been one of the potential interesting issues. One of the most important topics in this field is the study on hydraulic jump and its control method. Like other structures, in energy dissipaters considering economic and ease of construction is an essential issue. Therefore, in this study, the effects of the roughness and negative bed slope on water level and velocity profiles of hydraulic jumps for upstream flow in Froude numbers ranges of 4.9-7.8, with three different bed roughnesses and slopes of 0%, 3.1%, 60%, and % 2 were studied. The results indicated some similarities between the measured velocity profiles and some differences between the profiles of water jets as compared with those on smooth beds. Also, the thickness of the dimensionless boundary layer was calculated to be 0.66, which was significantly different in comparison with its value for the flat bed (0.16). Moreover, the bed shear stress on the rough negative sloping bed was at least 10 times greater than the shear stress on the smooth flat bed. Also, the energy and momentum correction coefficients were higher relative to the classic mode.
کلیدواژه‌ها [English]
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