Numerical Modeling of Flow Pattern at a Right-angled River Bend Using CCHE2D Model

Abstract

In this study, the CCHE2D model is used to analyse the flow pattern in a meander reach of the Gomati River. The finite volume method is used by the numerical model to solve the depth-averaged two-dimensional equations with 𝑘−𝜀turbulence closure. The numerical findings were compared with field data for two different flow rates in order to calibrate the CCHE2D model using various Manning's roughness coefficients. The results show that for the minimum and maximum discharges, a smaller Manning's roughness factor (0.015≥𝑛≥0.025)is more favorableto a higher Manning's roughness factor(0.030≤𝑛≤0.040). The results of the numerical model demonstrated that fluctuations in hydraulic parameters including shear stress, velocity, flow depth, and Froude number in the river bend are greatly influenced by the existence of centrifugal force and helical cells. The linear relationship between velocity and shear stress is presented across the whole study reach, as indicated by the R-squareand linear correlation coefficient (r) components. The results of the model show that the flow field within the river bend can be accurately simulated by the computational model.