Optimal Design of Wastewater Collection Systems

The most sought-after requirements of an optimization algorithm are with respect to computer time and memory. For the six-link system the time required for execution of a program is 70 sec on an IBM-360 (Model No.44) computer indicating that the algorithms are fast converging. Further, it takes only 75 sec to compile and load the program on a disk. The requirement of storage space is also very small. The total memory requirement on this computer is 9E8 bytes. A nonlinear algorithm based on Powell's method has been developed to optimize the design of wastewater collection systems. The algorithm is fast converging, requires small computer memory, employs the discrete set of commercially available diameters, and leads to a global optimum. The economics of optimal and conventional designs has been compared for a six-link wastewater collection system at Roorkee, India. A parametric study has also been presented.