Numerical Simulation of Jet Flow and Investigation Effect of Triangular Shape of Bucket, and Gate Opening Ratio on Flip Bucket Jet Flow Characters

If there is a high speed flow on a spillway and it is impossible to use a stilling basin because of its high cost or installation condition, the flip bucket may be used for energy dissipation. Flow-3D software was used in this research to simulate the flow on the chute spillway with ogee crest and flip bucket by volume of fluid (VOF) procedure and k-ε (RNG) turbulence model. At first, the numerical simulated trajectory of the jet flow was compared with the trajectory of the flow in the physical model, and also with the results of USBR, US Army and Kavakami equations. Then the effect of gate opening on the range length and the maximum height of the jet flow trajectory was studied. At last, the effect of the circular flip bucket shape and the two kind of triangular flip bucket named A and B on jet trajectory were studied. Results showed that USBR equation was more accurate than the numerical model and other empirical relationships in determination of the jet range length. Based on the results, two relationships were presented between gate opening VS reduction percentage of the range length and the maximum height of the jet. Comparison of the hydraulic characteristics of the circular and triangular flip buckets showed that the characters of the triangular flip bucket type A was more similar to that of the circular flip buckets in comparison to the type B and due to its easier implementation could be used instead of the circular flip bucket. In addition, results of the numerical model showed error ranges length of 12 and 8 percent for the maximum jet range length and maximum height, respectively. Therefore, applying numerical model of Flow-3D in estimating effects of bucket shape is recommended.