Leak Detection in Viscoelastic Pipe by Transient Analysis

The use of fluid transients has the potential to provide insight into effect of leaks in pipeline systems and hence provide leak detection method. This paper presents a technique for detection and location of leaks in a single viscoelastic pipe by means of transient analysis. The method uses transient pressure waves initiated by the sudden closure of an upstream valve. The presence of a leak in a pipe partially reflects these pressure waves and allows for the location and magnitude of leaks. The two constitutive equations of continuity and momentum yield a set of two partial differential equations of hyperbolic type. The viscoelastic behaviour of the pipe wall material is represented by a generalized Kelvin-Voigt model. The computed results obtained by the method of characteristics describe the influence of the leak on head and discharge time-histories. The effect of the pipe wall viscoelasticity on the leak detection and sizing is also discussed.