Enhancing Impact Localization from Fluid-Pipe Coupled Vibration under Noisy Environment

Round 1

Reviewer 1 Report

Add more details of localization procedure, e.g. formula.

There is no connection to pratical leak sizes. As an example, table 3 should be related to a leak size.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

This paper proposed an enhanced wavelet-based approach to detect and localize an impact source and a noise reduction algorithm to reduce the influence of transient noises. The two schemes are validated by experimental results. Compared with the conventional cross-correlation algorithm, the methods have some advantages in accuracy and stability. The paper is generally well written and the description of the mechanism in the circular water pipe and the analysis of the waves from different sources are presented clearly. The methods have some merits for the engineering application. In sum, acceptance for publication is recommended provided some minor modification based on the following comments are properly addressed.

-The authors mentioned that "Fig. 3(b), it is not hard to recognize the 
impact signal around 0.1 [sec] in time and 730 in scale," at line 252. But Fig.3b doesn't provide much details on how to determine 70 Hz. More explanation or technique details should be provided on how to obtain the assertion.

-For real application, the underground pipeline is not straight and it might contain curved parts or the variation of the directions. Can current schemes be applied to these scenarios? How is the wave propagation of water in curved pipelines? What if the branches of pipelines occur? Some comments on these aspects may be beneficial for the paper.

Author Response

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Reviewer 3 Report

The reviewed manuscript presents a method for localisation of pressure impacts in pipelines. The proposed method employs a continuous wavelet transform (CWT) of vibration signals measured on the pipeline's outer surface. Although the method address flow-induced random vibration (noise), its verification and possible application for monitoring appear to be doubtful. Therefore, discussion and some conclusions might be incorrect, and the manuscript should not be published as it is. Authors are encouraged to discuss their research more thoroughly and address the issues listed in the enclosed file.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

The reviewer would like to thank the authors for the revised manuscript and detailed discussion of the issues. Although the manuscript has been improved substantially, there are some additional remarks  in the enclosed file which the authors should address.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Round 3

Reviewer 3 Report

The reviewer would like to thank the authors for the revised manuscript. There are just some minor touches left for the final proof:
- the usage of units is inconsistent - some units are in square brackets [], some without brackets, some without the white space (line 250); the authors are encouraged to employ MDPI Style Guide in the final proof, see https://www.mdpi.com/authors/layout#_bookmark33
- seconds are labeled both (s) and (sec), the authors are encouraged to consolidate the labels,
- Tab. 2 is separated by the page break,
- captions should be at the same page as their respective figures, see Figs. 5 - 7 and 10.