Detection of plane sealing leakage by tuning the generated sound characteristics

Currently, on-line leakage detection of sealed surfaces is being researched to improve detection accuracy. This study presents a new method of leakage detection by generating sounds with two crests at frequencies of 11.0 kHz and 32.7 kHz using specially designed cavity shaped whistles. The sound pressure levels (SPLs) that are generated were significantly greater than the pressure levels of the leakage jet noise at the sealing surface. In addition, the occurrence of the crests (11.0 kHz and 32.7 kHz) was independent of the leakage rate, leakage channel size, and sensor location. The experimental results showed that the leakage detection sensitivity and accuracy of the presented method exceeded those of the commercial acoustic emission (AE) method. The simulations revealed that the frequency crests resulted from strong fluid pressure oscillations and symbolic opposite radiation reactance of cavity shaped whistle. The proposed leakage detection method shows great potential in real industrial applications due to its anti-disturbance and good accuracy. (C) 2019 Elsevier Ltd. All rights reserved.