Optimal design of multidiameter, multioutlet pipelines

Presented herein is an optimal design method for a multidiameter, multioutlet pipeline employing a dynamic programming approach. Optimal lengths of varying pipe sizes for a multioutlet pipeline are obtained by minimizing the annualized cost of the pipeline, which can include either fixed costs, energy costs or both. The Darcy–Weisbach formula is used to calculate friction head loss in various sections of the multioutlet pipeline. The primary input to the optimization model is the annual cost of all the available alternatives of single pipe sizes, and the output comprises the lengths of the selected diameters to form the total length of the multioutlet pipeline satisfying allowable limits on pressure variation. Applicability of the method is demonstrated through optimal design of a pipeline comprised of more than one diameter and serving as a sprinkler lateral for varying upward and downward slope conditions.