Energy Loss at the Base of a Free Straight Drop Spillway | Chapter 2 | Current Overview on Science and Technology Research Vol. 6

 Vertical drop or free overflow is a common feature of both natural and man-made canals. Natural drips are formed by bed erosion, while artificial drips are incorporated into irrigation systems to reduce canal slopes to design slopes. A gradual overflow results in greater energy loss. Greater energy dissipation is caused by the jet mixing with the pool at the downstream end of each droplet. As a result, this accounts for the reduced energy dissipation commonly present in drop chips and gradual overflows. In this work, we investigate the energy dissipation of linear droplets through the creation of a physical model. Effective geometric and hydraulic parameters were determined and three drops of different heights were made from plexiglass. These physics models were installed in his two existing channels at the Hydropower Laboratory at Tabriz University, Iran. Several runs of the physical model were performed to determine the key parameters for determining energy dissipation. The results show that droplet energy dissipation is affected by droplet height and ejection. The predicted relative energy dissipation varied from 10.0% (for yc/h = 0.94) to 94.3% (for yc/h = 0.02). Energy loss due to falling is primarily due to mixing of the jet with the pool behind the jet, which entraps air bubbles in the flow. A statistical model was developed to predict the energy dissipation of droplets that exhibits nonlinear correlations between effective parameters. Comparing this work with the results of his Moore, Rand, White, Rajaratnam and Chamani, White's model overestimates the droplet energy dissipation and Rand's model underestimates the droplet energy dissipation. I understand. Others can predict energy dissipation similarly to the proposed statistical model. The length of the downstream calm basin predicted by White is 20% shorter than the others.

Author(s) Details:

Farzin Salmasi,
Department of Water Engineering, Faculty of Agriculture, University of Tabriz, Tabriz, Iran.

John Abraham,
University of St. Thomas, Minnesota, School of Engineering 2115 Summit Avenue St. Paul, Minnesota 55105, USA.

Please see the link here: https://stm.bookpi.org/COSTR-V6/article/view/8412