Performance comparison of acoustic emission sensor arrays in different topologies for the localization of gas leakage on a flat-surface structure

The topology of the acoustic emission sensor array has an important effect on the performance of the leak localization technique. This paper compares the performances of different topologies of acoustic emission sensor arrays in the localization of gas leakage on a flat-surface structure. The principle of the leak localization is based on the near-field beamforming according to the spherical wave model and the narrowband filtering which can effectively avoid the influence of acoustic dispersion. The effect of different arrangements of the sensing elements in a sensor array on the localization accuracy is investigated and discussed. Eight typical topologies, including line, L-shaped, cross, triangle, star, circular, semi-circular and square shapes, are appraised through computer simulation. Simulation results suggest that all the arrays can perform leak localization but with different accuracies and that the L-shaped array outperforms all other topologies under the similar conditions. Furthermore, the optimal number of sensors in the L-shaped array which can maintain a reasonable accuracy of localization is analyzed. Experimental work was carried out on a laboratory scale test rig to verify and assess the effectiveness of the L-shaped array. The simulation and experimental results demonstrate that the L-shaped array is capable of identifying the location of a leak hole in a plate structure with a reasonably good accuracy.