Impact of the Soundproofing in the Cavity of the Synthetic Jet Actuator on the Generated Noise
Round 1
Reviewer 1 Report
In this paper, the authors experimentally test the soundproofing of a multi-orifice synthetic jet actuator. Four different types of soundproofing were tested by replacing one of the walls with the soundproofing material. The effects of resonant frequency and the sound pressure level (SPL) for all the cases are investigated. This paper is quite short, however, is of interest to the community. The paper is written well and I recommend the publication of this paper. I have the following questions though which they authors may wish to answer.
1. In Figure 2, what is causing the shift in resistance patter at different powers after about 100 Hz?
2. What is the cause of the oscillations that are observed in the SPL in Figure 3?
3. How do the authors establish that the measurements are indeed correct, are there any other data to compare the results or the measurement techniques?
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Dear Authors,
I have gone through your paper, and it appears to me that you need to improve english structure and grammar. Please, do this as I cannot recommend this publication without significant improvement in language. Furthermore, I strongly believe that you should plot the results in dBA, i.e. perform A-weighting. The latter will effectively show that using sound proofing in cavity for SJA is not useful, which is the central premise of your paper. Lastly, why have you plotted only frequencies till 150 Hz, this region is not very useful, as human ear is not very sensitive. This will be evidenced once you plot them.
There are some other minor corrections that I want you to address.
1) Please mention how was the accuracy of measurements determined to be +- 1.4 dB and resolution to be 0.1 dB.
2) For figure 4, plot same quantity but its integrated value, i.e. OASPL. This will help to quantify overall performance of the sound proofing.
3) Please report the background noise of your facility.
Finally, without an evaluation of noise at higher frequencies it is impossible to asses the performance and therefore your work will be of little to no interest to the scientific community. As such it is imperative your plot values upto at least 10 kHz.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Dear Authors,
Could you please clarify if the change in the SPL that you mentioned in your article is in db or dbA ?
If it is dBA, then please remove reference of dB through out the paper.
Minor Comments
You mention, "The actuator is loud and although the human ear is not very sensitive to these frequencies, staying close to a running SJA for a long time may cause headache and excessive fatigue."
If this is the case, Please provide a direct evidence as to how sound pressure level can determine or quantify these health concerns directly.
In the rebuttal you mention: "During the measurements A- weighting was used. Curve A is by default used in Testo 816-1. The information about this was added in lines 93-94. "
Please also update the y-axis labels so that it is clear when you present them.
I am looking forward to an revised version
Regards
Referee
Author Response
Dear Reviewer, please see the attachment.
Author Response File: Author Response.pdf
Round 3
Reviewer 2 Report
Dear Authors,
I have gone through the updated manuscript and I agree that the manuscript is ready for submission in the journal current form for publication
Regards
