Author(s): Jingrong Lin, Mohamed S. Ghidaoui
Linked Author(s): Jingrong Lin
Keywords: Leakage detection, frequency shift, frequency response function, transient.
Abstract: In recent years, an efficient and easy to apply transient-based frequency response method has been developed in use for pipeline leakage detection. Until now, it has been assumed that a leaking pipeline should have the same resonance peaks at all the odd harmonics in its frequency response diagram as an intact pipe. However, in this research, a small but undeniable leak-induced frequency shift in a leaking pipeline is demonstrated in the frequency response diagram of the leaking pipeline in both transfer matrix method and method of characteristic simulation. The expression for this leak-induced shift is derived using Taylor series expansion together with a transfer matrix. The verification of the shift expression is given, and the factors influencing the shift are discussed. The demonstrated leak-induced frequency shift are generally quite small and therefore do not significantly affect the utility of the Frequency Domain methods. However, it is important to note that such leakage induced frequency shifts are, in fact, real. Thus, this research and paper provide complementary knowledge and clarification to the frequency response leakage detection theory
Year: 2017