Low-Boom Design for Supersonic Transport with Canard and Forward-Swept Wings Using Equivalent Area Design Method
Round 1
Reviewer 1 Report
Please, check line 158: it might be "A Simple Low-dissipation Advection Upstream Split"
English is fine, just check for minor errors.
Author Response
We thank the referees for carefully reading our manuscript and providing useful comments. We have revised the manuscript “Low-Boom Design for Supersonic Transport with Canard and Forward-Swept Wings Using Equivalent Area Design Method” on the basis of the referee's comments.
We look forward to the publication of our manuscript in Aerospace.
Sincerely,
Yuki KISHI
Our response to the referee's comments are as follows:
(1) Please, check line 158: it might be "A Simple Low-dissipation Advection Upstream Split.”
Answer: We apologize for a misprint. It has been corrected in the manuscript.
Reviewer 2 Report
1) Section 3.2.1 - Recommend authors add some grid convergence study results to the manuscript in addition to the overall grid size, stated at 68million
2) Section 4.3 - Recommend adding some additional data regarding the effect of re-distributing the longitudinal lift distribution on the static margin of the configuration. The design to reduce noise makes sense, but only if practically implementable.
3) Table 4 shows modest reduction in PLdB between re-design and baseline. Recommend adding some data and/or citations about what a perceivable noise difference is to a ground based observer. I'm not convinced that a 2dB OASPL is noticeable by the human ear.
Some sentence structure, such as the two examples (of many in the article) below, can be improved throughout the article to be more natural sounding:
"There is few research regarding an actual supersonic transport (SST) with forward-swept wings." Writing 'there is few' is not natural, perhaps "There is little research concerning SST configurations with forward-swept wings."
"However, forward-swept wings are among the highly potential concepts for low-drag, low-boom wing planforms." Perhaps "Forward-swept wings remain a potential concept for low-drag, low-boom SST configurations."
Many small improvements possible throughout the manuscript, with two pointed out above.
Suggest:
Author Response
Our answers for your review are written in attached PDF file. Please check it.
Author Response File: 
Author Response.pdf
Reviewer 3 Report
The paper is well structured and logically built. The comparison between the different configurations in term of pressure distribution (figure 12) would be clearer if the planform of the aircraft would have been shown below the graph. The same could be applied to figures 7 and 8 that could be combined, side by side, with figure 6. Apart from adding the canard, the reduction in perceived noise level between the different configurations is insignificantly low (1 dB is the minimum difference that can be subjectively felt, and the results show a reduction of less than two tenths of a dB in the best case). It is doubtful that this would be worth it unless the aerodynamic efficiency does not suffer at all.
Good level of english overall, some typos to be checked (e.g. line 158, "disspaition"). At line 57, replace "is resulted from the" with "derives from". At line 320, use either "without" or "w/o", not both. At line 510, remove "wing" after "horizontal tail"; at line 445, remove "owing".
Author Response
We thank the referees for carefully reading our manuscript and providing useful comments. We have revised the manuscript “Low-Boom Design for Supersonic Transport with Canard and Forward-Swept Wings Using Equivalent Area Design Method” on the basis of the referee's comments.
We look forward to the publication of our manuscript in Aerospace.
Sincerely,
Yuki KISHI
Our response to the referee's comments are as follows:
(1) The paper is well structured and logically built. The comparison between the different configurations in term of pressure distribution (figure 12) would be clearer if the planform of the aircraft would have been shown below the graph. The same could be applied to figures 7 and 8 that could be combined, side by side, with figure 6.
Answer: As you pointed out, we added the planforms of the aircrafts in Figure 12, 7 and 8.
(2) Apart from adding the canard, the reduction in perceived noise level between the different configurations is insignificantly low (1 dB is the minimum difference that can be subjectively felt, and the results show a reduction of less than two tenths of a dB in the best case). It is doubtful that this would be worth it unless the aerodynamic efficiency does not suffer at all.
Answer: As you mentioned, with the exception of the canard wing, the sonic boom reduction owing to the redesign is small. It reveals that the variation in wing planform from the desC1 configuration to the desW1 configuration was likely to have been inadequate to affect the PLdB. To reduce sonic boom more, more drastic redesign such as the simultaneous modification of wing and fuselage. However, the scope of this study is the validation of sonic boom reduction by mounting the canard wing to the SST with forward-swept wings. Thus, we think useful knowledge was obtained in this study. We have added the explanation to the manuscript as a follow.
(Section 4.6, 1st paragraph, 11th sentence)
Therefore, the variation in wing planform from the desC1 configuration to the desW1 configuration was likely to have been inadequate to affect the PLdB. To reduce the PLdB value further, radical redesign should be required such as the simultaneous modification of wing and fuselage.
(Section 4.6, 1st paragraph, 11th sentence)
Therefore, the variation in wing planform from the desC1 configuration to the desW1 configuration was likely to have been inadequate to affect the PLdB. To reduce the PLdB value further, radical redesign should be required such as the simultaneous modification of wing and fuselage.
(3) Good level of english overall, some typos to be checked (e.g. line 158, "disspaition").
Answer: We apologize for a misprint. It has been corrected in the manuscript.
(4) At line 57, replace "is resulted from the" with "derives from".
Answer: We have revised the manuscript as you pointed out.
(5) At line 320, use either "without" or "w/o", not both.
Answer: We have revised the manuscript as a follow.
(Section 4.3, 4th paragraph, 1st sentence)
Figures 8 show the local lift distribution along the body axis of each configuration. In this figure, the first peak of each configuration with the canard wing corresponds to the lift generated by the canard wing.
(6) At line 510, remove "wing" after "horizontal tail"
Answer: We have revised the manuscript as your feedback.
Round 2
Reviewer 2 Report
The authors have appropriately addressed the feedback.
Author Response
Dear Reviewer 2
We thank you for carefully reading again.
We look forward to the publication of our manuscript in Aerospace.
Sincerely,
Yuki KISHI, Risato YASHIRO, Masahiro Kanazaki
