Effect of approach length and angle of ski jump on the outlet trajectory

Subject Areas : Farm water management with the aim of improving irrigation management indicators

Mona Omidvari Nia ¹ (Ph.D Candidate of ShahidChamran University, Ahwaz, Iran)
Seyed Habib Musavi-Jahromi ² (Associate Professor and head of department of Hydraulic structure, ShahidChamran University, Ahwaz, Iran.)

Received: 2012-01-06 Accepted : 2012-04-20 Published : 2012-09-02

Keywords: approach length, jet trajectory, physical model, tri-angular Flip bucket,

Abstract :

Design and optimum selection of the hydraulic structures characteristics, plays very important role in water resources management in agricultural sector. In this study, ski jump of triangular flip bucket is investigated. To process the project, a physical model including a flume and an ogee weir were designed and constructed. Three flip bucket including a flip bucket with 45 degree angle and 2 cm length, flip bucket with 45 degree angle and 7 cm length and a flip bucket with 22.5 degree angle and 2 cm length. Four discharges and their corresponding Froude number were considered. The length of trajectory, upper and lower limits of jet flow were then measured and the required data were collected. The results indicated that increasing of bucket angle causes the thickness of jet trajectory increases. It is shown that Flip bucket with 45 degree angle and 7 cm length of the approaching canal is more effective than the others. It is further shown that the length of approaching canal has no significant role on the jet trajectory. Moreover, it is revealed that the angle of the bucket plays a significant role on the jet trajectory's characteristics. Increasing Froude number from 4.44 to 6.42 lead to upper and inferior of jet trajectory to be increased to 72.5 and 77.7 percents, respectively.