26. Energy and Momentum Correction Coefficients in Compound Open Channel Flow

Open channels have a wide range of applications directly or indirectly in our day-to-day life. Irrigation canals, waste water channels, sewers etc. are some of the practical examples of free-surface flow channels. Study of the hydraulic properties of open channel is a prime part of river engineering. This article presented a novel approach to model the two energy correction coefficients (kinetic energy and momentum coefficients) by collecting experimental data sets on rough asymmetric channels. In the present work, two sets of experiments were conducted on a compound asymmetric channel having two types of roughness material on the flood plain (plastic mat and gravel). To develop the models a wide range of data sets has been considered which includes asymmetrical compound channels with smooth or differential roughness cases. For the current work, multivariate regression analysis was used to develop ameliorated models to anticipate error-free values of the energy correction factors. Multivariate regression analysis is used to predict dependent variables from a number of independent variables. In this present study, for implementing multivariate regression analysis, the two correction factors (Energy correction factor α and momentum correction factor β) were chosen as dependent variable and aspect ratio (δ = b/h), roughness ratio (γ = n_fp/n_mc), Reynolds No. (R_e) and Froude’s No. (F_r), width ratio (α₁ = B/b), relative depth (Dr = (H − h)/H) are taken as independent variable. Error analysis was performed to determine the accuracy of the present models.