Modeling Elastically Deforming Leaks in Water Distribution Pipes

In this study, the relationship between the conventional power equation and the fixed and variable area discharges (FAVAD) equation for modeling leakage as a function of pressure was investigated. It is shown that different leakage exponent (or N1) values are obtained for the same leak when measured at different pressures. An analytical exploration of the two equations shows that the leakage exponent tends to 0.5 when the system pressure tends to zero, and to 1.5 when the system pressure tends to infinity. A dimensionless leakage number LN is defined as the ratio between the variable and fixed portions of a leak, and it is shown that a single function can be used to describe the relationship between the leakage number and leakage exponent. This model was combined with previous research to accurately predict the leakage exponents of several published studies in cases where elastic deformation occurred.