Closure to ¿Gradually Varied Flow Computation in Cyclic Looped Channel Networks¿ by H. Prashanth Reddy and S. Murty Bhallamudi

A simplified method for the resolution of lateral hydraulic problems in laminar and turbulent flow is presented. In the first stage, the head losses are calculated by applying the Darcy–Weisbach equation with a discrete and constant outflow model, which leads to a correction parameter equivalent to Anwar’s Ga factor. The difficulty that arises from variation of the friction factor along the lateral (due to discharge flow) is overcome by means of an equivalent friction factor (feqN). In the second stage, this head loss model is used together with a variable discharge model based on Taylor polynomials to make a better estimate of the flow rate distribution by means of a successive-approximations scheme. This new approach directly allows the computation of the real mean lateral’s outflow and the minimum and maximum discharges. In the third stage, the previous results can be improved (if desired) by taking into account the nonconstant outflow distribution model developed in the previous stage. The method prop...

Equivalent Friction Factor Method for Hydraulic Calculation in Irrigation Laterals

This paper presents an efficient solution technique for one-dimensional unsteady flow routing through a general channel network system—dendritic, looped, divergent, or any combination of such networks. The finite difference method is used to solve the de St. Venant equations in all the branches of the network simultaneously. The number of equations to be solved at a time during any iteration is reduced to only four times the number of branches of the network. This results in a significant reduction in storage requirements and solution time. Importantly, the algorithm does not require any special node numbering schemes and the nodes can be numbered independently for each branch. The algorithm is also suitable for programming on a parallel-processing computer.

Closure to ¿Gradually Varied Flow Computation in Cyclic Looped Channel Networks¿ by H. Prashanth Reddy and S. Murty Bhallamudi

References

Equivalent Friction Factor Method for Hydraulic Calculation in Irrigation Laterals

Efficient Algorithm for Gradually Varied Flows in Channel Networks