Design of Straight Expansive Pipe Transitions

Pipe transitions frequently occur in piping networks such as a water distribution system, or piping in a chemical engineering plant. Whereas the contraction transitions involve less head loss, the expansion transitions involve a sizable head loss. Considerable energy savings can be achieved if the transitions are designed by minimizing the head loss. The conservation of energy will be significant if the transition is meant for a steel-lined power tunnel where the flow velocities are high. Similarly, in a system having frequent occurrence of transitions, such as a high-rise building or plan of a city, the optimum transition profile can be used most effectively. This paper uses optimal control theory to develop a methodology for optimal design of expansion pipe transitions. Analyzing a large number of designed optimal transitions; empirical design equations for the pipe diameter profile are obtained.