نوع مقاله : مقاله پژوهشی
1 کارشناسی ارشد سازههای آبی، گروه علوم و مهندسی آب، دانشکده کشاورزی، دانشگاه بیرجند.
2 استادیار گروه مهندسی آب،دانشگاه بیرجند
3 استادیار گروه علوم ومهندسی آب ، دانشکده کشاورزی ، دانشگاه بیرجند
4 استاد گروه علوم و مهندسی آب دانشگاه بیرجند
عنوان مقاله [English]
The aim of this study was to investigate the effect of jet and reverse slope on the characteristics of hydraulic jump. This study was performed inside a flume in the form of a rectangular channel 10 meters long and 30 cm wide. Free jet with flows of 2, 2.5 and 3.2 liters per second with the maximum displacement angle of the beginning of the jump and the angle without changing the beginning of the jump to the end of the hydraulic jump. The results showed that changes in the angle and flow rate of the jet reduce or increase the secondary depth, jump length, relative energy loss and shear stress force of the bed. Using a jet with a maximum angle and flow rate of 3.2 liters per second with the lowest landing number Reverse flow and slope reduced the secondary depth ratio by about 56.2% compared to the no-jet mode and smooth bed. Using a jet with a minimum angle and flow rate of 3.2 liters per second and the maximum flow rate increased the secondary depth ratio relative to Jetless mode was smoothed. The results of this study show that at a certain angle from the jet to the hydraulic jump, there is no displacement in the jump, which was named as the inert angle, and by increasing the angle of the jet jump upwards, the hand jumps to It moves upstream and from one angle onwards the jump does not move upwards. This angle was named as the maximum displacement angle. Changes in the angle and flow rate of the jet reduce or increase the secondary depth, jump length, relative energy drop and stress force. The use of a jet with a maximum angle (138 degrees) and a flow rate of 3.2 liters per second, the minimum number of landings (6.64) and reverse slope reduces the ratio of the secondary depth to about 56.2% relative to the state without jet and bed was smoothed. Using the jet with the minimum angle (78 degrees) and the flow rate of 3.2 liters per second and the maximum number of landings (9.62) flow increased the ratio of secondary depth by 15.3 percent compared to the state without jet and smooth bed.