Optimum Pipe Size Selection for Turbulent Flow

Pipelines are normally designed to deliver fluid at the required head and flow rate in a cost effective manner. Increase in conduit diameter leads to increase in annual capital costs, and decrease in operating costs. Selection of an optimum conduit diameter for a particular fluid flow will therefore be a vital economic decision. This paper presents a computer aided optimisation technique for determination of optimum pipe diameter for a number of idealized turbulent flow. Relationships were formulated connecting theories of turbulent fluid flow with pipeline costing. These were developed into a computer program, written in Microsoft Visual C++ language, for a high-level precision estimate of the optimum pipe diameter, through the least total cost approach. The validity of the program was ascertained through case studies, representative of fluids with different densities and compressibility. The optimum conduit diameter was found to increase linearly with increase in compressibility.