A SEGREGATED CFD APPROACH TO PIPE NETWORK ANALYSIS

The most popular pipe network algorithms fall into three categories depending on whether node, loop or element solving equations are considered. Although node methods have some advantages over the other two methods, some authors have found the node methods to be more unreliable than the other two classes of methods. Node methods are also used in Computational Fluid Dynamics (CFD) to solve the Navier-Stokes equations. Since significant progress has been made in this held in the recent past it was felt that this Should have some bearing on the development of more reliable node methods for pipe network problems. In this paper the well-known SIMPLE algorithm of Patankar and Spalding,(1) which is known in CFD as a segregated method, is extended to deal with pipe network problems. The method can deal with both compressible and incompressible flows. Special attention is given to the solution of the pressure correction equation, the stability of the algorithm, sensitivity to initial conditions and convergence parameters. It is shown that the present method is not very sensitive to initial conditions. The method is very reliable and it deals more effectively with compressible flows than the conventional Newton-Raphson method for incompressible flows.