Limits for leak noise detection in gas pipes using cross correlation

The cross correlation method is widely used in leak detection and location for pipes. The model of the cross correlation function of the leak noise for water pipes has been established in an earlier study, while there is no such model for gas pipes. In this study, a model of the correlation function of the leak noise in gas pipes is developed. The characteristics of wave propagation in gas pipes, combined with the leak noise spectrum, are incorporated into the model to consider the effects of physical parameters, i.e., turbulence parameters, pipe parameters and flow parameters, on the cross correlation function. This model is capable of describing the main features of the correlation results in gas pipes. Moreover, the model gives an estimation of the detection limits of the leak noise in the absence of noise, which is crucial to the deployment of sensors in real gas pipelines. The findings of this study provide theoretical insight and experimental evidence for optimizing the cross correlation method when conducting leak detection and location in gas pipes.