COMPARATIVE EFFICIENCIES STUDY OF SLOT MODEL AND MOUSE MODEL IN PRESSURISED PIPE FLOW

Abstract

The flow in sewers is unsteady and variable between free-surface to full pipe pressurized flow. Sewers are designed on the basis of free surface flow (gravity flow) however they may carry pressurized flow. Preissmann Slot concept is widely used numerical approach in unsteady free surface-pressurized flow as it provides the advantage of using free surface flow as a single type flow. Slot concept uses the Saint-Venant’s equations as a basic equation for one-dimensional unsteady free surface flow. This paper includes two different numerical models using Saint Venant’s equations. The Saint Venant`s equations of continuity and momentum are solved by the Method of Characteristics and presented in forms for direct substitution into FORTRAN programming for numerical analysis in the first model. The MOUSE model carries out computation of unsteady flows which is founded on an implicit, finite difference numerical solution of the basic one dimensional Saint Venant’s equations of free surface flow. The simulation results are compared to analyze the nature and degree of errors for further improvement.