Developing formulae for discharge coefficient in curved weirs using Genetic Programming

Curved weirs in plan due to their special hydraulic conditions as well as long crest، have suitable capability in effective water surface regulation in irrigation canals and networks. Also، these weirs have high turbulence intensity in downstream and make better conditions for rivers، in environmental point of view. There are few studies regarding calculation of curved weirs’ discharge coefficient and their head discharge equation. In this study، using new optimization method of genetic programming، a dimensionless equation for discharge coefficient has been proposed based on two non-dimensional parameters of weir angel and ratio of water head to weir height. For training and testing of the proposed equation، experimental data of Kumar et al، have been used. Comparison of results obtained from this equation with the experimental data reveals high accuracy of the new equation of genetic programming. Mean absolute errors of the proposed equation for discharge coefficient have been calculated as 1. 36 and 1. 65 percent، for training and testing phases، respectively. This error for non-linear equation of Kumar et al، is nearly 9. 4 percent.