A Mathematical Approach for Sound Insulation Characteristics and Cost Optimization of Double-Layer Composite Structures
Round 1
Reviewer 1 Report
Comments to Author
The authors investigated the sound insulation properties of nonwoven/polyvinyl chloride composite for the application of compressor noise insulation, it is an interesting topic.
The manuscript is informative, but some imperfections need to be improved.
- Some publications in the field of sound absorption of nonwoven materials are recommended to the authors:
T. Yang, X. Xiong, R. Mishra, J. Novák, and J. Militký, Text. Res. J. 89, 612 (2019).
P. Segura-Alcaraz, J. Segura-Alcaraz, I. Montava, and M. Bonet-Aracil, J. Ind. Text. 1 (2019).
Besides, a review regarding the sound absorption of fibrous material is recommended:
T. Yang, L. Hu, X. Xiong, M. Petrů, M.T. Noman, R. Mishra, and J. Militký, Sustain. 12, 1 (2020).
- Figure 3 presents the correlation between the experimental and predicted results. If the prediction is based on the model developed from the experimental results via the least square method. Definitely, the correlation coefficient is more than 0.99.
- Table 4 is the same as Table 3, please correct it.
Author Response
Dear reviewer:
Thank you very much for your review of my paper. Your comments are very valuable to me. According to your comments, we have revised and added supplement to the paper.
The detail description please refer to the attachments.
1.Some publications in the field of sound absorption of nonwoven materials are recommended to the authors:
- Yang, X. Xiong, R. Mishra, J. Novák, and J. Militký, Text. Res. J. 89, 612 (2019).
- Segura-Alcaraz, J. Segura-Alcaraz, I. Montava, and M. Bonet-Aracil, J. Ind. Text. 1 (2019).
Besides, a review regarding the sound absorption of fibrous material is recommended:
- Yang, L. Hu, X. Xiong, M. Petrů, M.T. Noman, R. Mishra, and J. Militký, Sustain. 12, 1 (2020).
Response: Thank you for your valuable suggestion. The author has supplemented these necessary references.
2.Figure 3 presents the correlation between the experimental and predicted results. If the prediction is based on the model developed from the experimental results via the least square method. Definitely, the correlation coefficient is more than 0.99.
Response: The author did use the least square method to fit the experimental data, thus obtaining the undetermined coefficients in the mathematical model. But sometimes it will be affected by the difference of experimental results, and it is also quite good to get a goodness of fit of 0.99.
3.Table 4 is the same as Table 3, please correct it.
Response: Thank you for your valuable suggestion. The author has corrected Table 4.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This study about the sound insulation characteristics and cost optimization of double-layer composite structure focuses more on this last target but explains pretty well also the first one.
The paper itself is pretty clear to me and i don't see any major problem with it. I would love to see an angular array of microphones to check eventual asymmetric behavior (or the same mic could be shifted at different angles).
Regarding the optimization process it would be better to include few lines about the parametrization needed in case the actual material costs vary, since the surface upon which the minimization is found have non-linear gradients.
Other little suggestions are:
Figure 4 can be (if needed) shrunken. It does not need such big space.
Figure 5: it may be cool to see here the same blue intersecting line we see in Fig.6.
Out of my personal curiosity: did you checkd what happens if you double the double-layer composite structure? is it going to halves the values of the third column in table 2? or it will show non-linear convulution effects? a little study on this could improve the next paper by discussing how different materials convolute themselves.
The paper can then be a go for me.
Author Response
Dear reviewer:
Thank you very much for your review of my paper. Your comments are very valuable to me. According to your comments, we have revised and added supplement to the paper.
The detail description please refer to the attachments.
This study about the sound insulation characteristics and cost optimization of double-layer composite structure focuses more on this last target but explains pretty well also the first one.
The paper itself is pretty clear to me and i don't see any major problem with it. I would love to see an angular array of microphones to check eventual asymmetric behavior (or the same mic could be shifted at different angles). Regarding the optimization process it would be better to include few lines about the parametrization needed in case the actual material costs vary, since the surface upon which the minimization is found have non-linear gradients.
Response: Arranging microphones in multiple directions can better analyze the directivity of compressor noise radiation. However, this paper mainly focuses on the analysis of sound insulation effect of sound insulation structure. So the microphone is only arranged in one direction in this paper. The author plans to study the noise radiation characteristics of the compressor with review expert suggestions.
Other little suggestions are:
Figure 4 can be (if needed) shrunken. It does not need such big space.
Response: Thank you for your valuable suggestion. The author readjusted Figure 4. Now Figure 4 is smaller.
Figure 5: it may be cool to see here the same blue intersecting line we see in Fig.6.
Response: Thank you for your valuable suggestion. The author marked the intersection line (blue line) of two surfaces in Figure 5
Out of my personal curiosity: did you checked what happens if you double the double-layer composite structure? is it going to halves the values of the third column in table 2? or it will show non-linear convolution effects? a little study on this could improve the next paper by discussing how different materials convolute themselves.
Response: The question of the review expert is an interesting and worth studying direction. In fact, we are already carrying out relevant research, for example, three-layer and four-layer composite sound insulation structure. We are looking forward to publishing it soon.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The revised manuscript can be accepted.
Reviewer 2 Report
After the minor revision the paper is now ready to be published.
Thank you for the opportunity to read your study.
