Prediction of gradually diverging hydraulic jump characteristics

In this study, regression equations were derived for estimation of sequent depth ratio and relative jump length in gradually expanding stilling basin with trapezoidal and rectangular cross sections.Non-dimensional parameters were derived from the effective parameters in hydraulic jump using Buckingham π-theorem. Finally, 5 arrangements of parameter for estimation of sequent depth ratio and relative length of jump in trapezoidal stilling basin and 5 arrangements for the estimation of sequent depth ratio and relative jump length in rectangular basin were generated.The best equations for the sequent depth ratio and jump length were selected by comparison between the models, using R2 and RMSE. The best equations to estimate the sequent depth ratio and relative jump length in gradually expanding stilling basin with rectangular section were found with R2=0.989, EF=0.9895, RMSE=0.21264 and R2=0.951, EF=0.9528, RMSE=0.001949 respectively. By the same way, the best equations for estimation of the sequent depth ratio andrelative jump length in gradually expanding hydraulic jump with trapezoidal section were found with R2=0.964, EF=0.9654, RMSE=0.318 and R2=0.951, EF=0.9505, RMSE=3.159 respectively.Evaluation of the models with the experimental data shows that the models can fairly predict the characteristics of expanding hydraulic jump in rectangular and trapezoidal cross sections.