Abstract
In steady flow, unsteady flow equations must be satisfied since the steady flow is a special case of the unsteady flow. The purpose of this study is to develop a flexible method for the analysis of hydraulics of sprinkler irrigation systems and design of its laterals based on the unsteady flow principle. Any sprinkler irrigation system can be analyzed if an objective program is made in a simple way. The analyzing method-based on unsteady flow principle-is simple and we can apply it in the design of field irrigation systems. In steady state analysis, the role of wave speed is not an important issue, because there is no actual wave speed in the pipeline when the final state is achieved. Therefore, a pseudo wave speed is selected which is convenient for the calculation of steady state heads and discharges. An algorithm is developed for the efficient calculation of heads and discharges at each node and riser end. The results obtained by unsteady flow method (UFM) are compared with the results obtained by a step by step method (SBSM) and they are found almost same. In this paper, the development technique of the algorithm, the design of best lateral size, and the analytical results of a sprinkler irrigation system are presented.
