Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

 

Overall, this manuscript is well written. I recommend it for publication after minor revisions.

 

Comments:

• Sec 2 and 3.2:  Please elaborate more on how you performed aerodynamic shape design and optimization. For example, what software did you use for optimization and CFD? What CFD model (RANS, LES, etc)? How did you model propellers in the CFD model?
• What do you mean by “0-loss”? The authors mentioned 0-loss a couple of times throughout the manuscript, but I could not understand what it exactly meant. Please elaborate.

 

Minor comments:

• Live Virtual Constructive: “constructive” is an adjective, but you should use a noun for this term. Or is it something people use in the literature? “LVC environment” is fine, but it sounds weird to use “LVC” as a noun.
• Please do not stretch/shrink the figures. For example, the characters in Fig. 2 look too narrow; I believe the authors shrunk the original figure in the horizontal direction.
• Table 2 caption should be edited.
• Eq. 9-10 are not displayed properly.
• Fig 22 (d); why trajectory is colored? what does the color variation mean? If the color has a meaning, a colorbar and explanation should be present.
• Page 20, L542 - it would be nice to include another figure showing how it behaved under transition. From Fig. 24, I cannot see what happened in transitions because of the time horizon of the test is much longer than the transition duration. Transitions just appear as a vertical jump in this figure. You could provide a zoom-in figure of the forward and reverse transition maneuvers.

Author Response

Dear Reviewer,

I hope this message finds you well.

Thank you very much for your thorough review and valuable feedback on our manuscript titled “[Rapid Integrated Design Verification of eVTOL UAVs Based on Modified Model-Based Systems Engineering]”. We appreciate the time and effort you have dedicated to providing insightful comments and suggestions. Below, we have addressed each of your points in detail.

1. Revising Report

First of all, I would like to once again express our sincere gratitude to the reviewer for the detailed review and constructive comments provided. These comments are valuable and helpful for revising and improving our manuscript and have significant guiding implications for our research. Your invaluable input has greatly assisted us in enhancing the rigor and quality of our manuscript. We have studied comments carefully and have made correction which we hope meet with approval. The summary of corrections and the responses to the reviewer's comments are listed below.

 

2. Responses to reviewer

Comments 1: [Sec 2 and 3.2:  Please elaborate more on how you performed aerodynamic shape design and optimization. For example, what software did you use for optimization and CFD? What CFD model (RANS, LES, etc)? How did you model propellers in the CFD model?]

Response 1: Thank you for your constructive comments, which have greatly helped improve the quality and clarity of our manuscript. We apologize for any inconvenience caused by previous omissions in the manuscript and sincerely appreciate your detailed feedback.

In response to your suggestion, we have added clarifications at the beginning of Section 3.2 to elaborate on the aerodynamic shape design and optimization process. The newly added content is as follows:

“Aerodynamic shape design and optimization play a critical role in achieving the performance requirements of the DB1 UAV. To conduct this process, we employed ANSYS Fluent for CFD simulations and design iterations. The RANS model with the k-omega SST turbulence model was adopted, as it provides a good balance between computational efficiency and accuracy in predicting boundary layer behavior. Propeller effects were modeled using the Actuator Disk Model [43], where distributed momentum sources represent the thrust and torque generated by the propellers. This method allowed us to efficiently analyze aerodynamic parameters such as lift-to-drag ratios, load factors, and flow field characteristics across various flight conditions. The insights gained from these simulations informed the iterative optimization of the DB1 UAV's aerodynamic shape.”

We believe this additional explanation addresses your concerns and enhances the technical clarity of the manuscript. Your attention to detail and helpful guidance have been invaluable, and we are grateful for your understanding and patience throughout the review process

 

Comments 2: [What do you mean by “0-loss”? The authors mentioned 0-loss a couple of times throughout the manuscript, but I could not understand what it exactly meant. Please elaborate.]

Response 2: Thank you for your valuable feedback and suggestions, which greatly contributed to improving the quality and clarity of our manuscript. We apologize for any confusion caused during the review process and appreciate your patience.

In response to your comment, we have added a note on "zero-loss" in the conclusion section, which is now explained as follows:

"The term 'zero-loss' refers to our methodology's ability to reduce unnecessary damage to aircraft prototypes during testing caused by design flaws. By identifying and correcting potential issues in the digital development phase, we minimize the risk of costly and destructive errors in physical testing, thus ensuring a more efficient and cost-effective development process."

We believe this addition clarifies the significance of our approach and enhances the overall understanding of our methodology.

Once again, we thank you for your detailed review and constructive suggestions, which have been invaluable in improving the readability and accuracy of our manuscript.

 

Comments 3: [Live Virtual Constructive: “constructive” is an adjective, but you should use a noun for this term. Or is it something people use in the literature? “LVC environment” is fine, but it sounds weird to use “LVC” as a noun.]

Response 3: Thank you for your valuable feedback and constructive comments. I apologize for any confusion caused during the review process and appreciate your patience.

In response to your suggestion, we have made the necessary revisions to improve the clarity of the manuscript. Specifically, we have replaced "Constructive" with "Construct" and changed all instances of "LVC" to "LVC environment," in line with your recommendation.

We believe these revisions have significantly enhanced the readability and precision of our manuscript. Thank you again for your thoughtful guidance, which has greatly contributed to improving the overall quality of our work.

 

Comments 4: [Please do not stretch/shrink the figures. For example, the characters in Fig. 2 look too narrow; I believe the authors shrunk the original figure in the horizontal direction.]

Response 4: Thank you for your valuable feedback. We apologize for the issue with the appearance of the characters in Figure 2. In response to your comment, we have corrected the figure by ensuring that the aspect ratio is maintained, and we have resized it appropriately to prevent any distortion. The font size and spacing have also been adjusted to ensure better clarity and readability.

We believe this revision addresses your concern and improves the presentation of the figure. Thank you again for your helpful comments, which have contributed to enhancing the quality of the manuscript.

(a)	(b)

 

Comments 5: [Table 2 caption should be edited.]

Response 5: Thank you for your valuable feedback and constructive comments, which have greatly improved the clarity and readability of our manuscript. I apologize for any inconvenience caused during the review process and appreciate your patience.

In response to your suggestion, we have revised the caption for Table 2 to ensure it more accurately reflects the content and purpose of the table. The updated caption is now:

"Table 2. Technical Parameters for UAVs from Demand Analysis."

We believe this revision significantly enhances the clarity and relevance of the table.

Thank you again for your thoughtful suggestions and helpful guidance, which have greatly contributed to improving the quality of our manuscript.

 

Comments 6: [Eq. 9-10 are not displayed properly.]

Response 6: Thank you for your valuable feedback and constructive comments. I apologize for any confusion caused during the review process and appreciate your patience.

In response to your comment regarding the formatting of Equations 9 and 10, we have reviewed and corrected their alignment and font size to ensure they are displayed clearly and consistently. These revisions improve the presentation of the equations and enhance their readability.

	(8)
	(9)
*sin	(10)

We believe this revision addresses your concern and significantly improves the clarity of the manuscript.

Thank you again for your thoughtful suggestions, which have contributed to enhancing the quality of our work.

 

Comments 7: [Fig 22 (d); why trajectory is colored? what does the color variation mean? If the color has a meaning, a colorbar and explanation should be present.]

Response 7: Thank you for your valuable feedback and constructive comments, which have greatly improved the readability of our manuscript. I apologize for any confusion caused during the review process and appreciate your patience.

In response to your insightful comment regarding Fig. 22 (d), we have unified the color scheme of the flight trajectory to simplify the visualization. Since this is a trajectory plot, the color variation does not carry any specific meaning, and we have updated the figure caption accordingly. Consequently, no colorbar is needed.

Figure 22 (d)

We believe this revision addresses your concern and enhances the clarity of the figure.

Thank you again for your thoughtful suggestions and helpful guidance, which have significantly contributed to the improvement of our manuscript.

 

Comments 8: [Page 20, L542 - it would be nice to include another figure showing how it behaved under transition.]

Response 8: Thank you for your valuable feedback and constructive comments. I apologize for any confusion caused during the review process and appreciate your patience.

In response to your suggestion, we have included additional zoomed-in figures to better illustrate the UAV's behavior during transition maneuvers. Specifically, Figure 24(b) has been enhanced to provide a clearer view of the transition phase by zooming in on the forward and reverse transitions. These zoomed-in views capture the rapid changes during transition, eliminating the ambiguity caused by the vertical jumps in the initial plot. This provides a clearer understanding of the transition dynamics.

Figure 24 (b)

The updated figures now present the transition details more comprehensively, allowing for a better analysis of the UAV's performance during this critical phase.

Thank you again for your thoughtful suggestions, which have significantly improved the manuscript.

 

Comments 9: [From Fig. 24, I cannot see what happened in transitions because of the time horizon of the test is much longer than the transition duration. Transitions just appear as a vertical jump in this figure. You could provide a zoom-in figure of the forward and reverse transition maneuvers.]

Response 9: Thank you for your insightful suggestion regarding the presentation of the transition maneuvers in Figure 24. We understand that the original figure, due to the extended time horizon, made it difficult to observe the UAV's behavior during the critical transition phases, as they appeared as vertical jumps.

To address this, we have revised Figure 24(b) by including zoomed-in views of the forward and reverse transition maneuvers. These additional views provide a clearer representation of the UAV's dynamics during these short-duration events, highlighting the rapid changes in pitch angle and other relevant parameters.

 

Figure 24 (b)

The updated figure ensures that the transition phases are presented in sufficient detail, offering a more comprehensive understanding of the UAV's performance. We believe this enhancement addresses your concern and significantly improves the clarity and readability of the manuscript.

We appreciate your valuable feedback, which has greatly helped us improve the quality and clarity of our work.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

file attached

Comments for author File: Comments.pdf

Author Response

Dear Reviewer,

I hope this message finds you well.

Thank you very much for your thorough review and valuable feedback on our manuscript titled “[Rapid Integrated Design Verification of eVTOL UAVs Based on Modified Model-Based Systems Engineering]”. We appreciate the time and effort you have dedicated to providing insightful comments and suggestions. Below, we have addressed each of your points in detail.

1. Revising Report

First of all, I would like to once again express our sincere gratitude to the reviewer for the detailed review and constructive comments provided. These comments are valuable and helpful for revising and improving our manuscript and have significant guiding implications for our research. Your invaluable input has greatly assisted us in enhancing the rigor and quality of our manuscript. We have studied comments carefully and have made correction which we hope meet with approval. The summary of corrections and the responses to the reviewer's comments are listed below.

2. Responses to reviewer

Comments 1: [ ... , however, an indicative value of what this benefit could mean has not been provided. An estimate on this could be interesting.]

Response 1: Thank you for your constructive feedback. We appreciate your positive comments on the methodology and its description.

Regarding your suggestion to include an estimate of time and cost savings, we would like to explain that this project is primarily carried out by students, and the costs associated with producing UAVs can be difficult to quantify due to the variability in production and processing costs across different locations. Additionally, our methodology aims to address key challenges in the UAV design process, specifically:

1. Avoiding mismatches between the design and mission requirements: This ensures that the UAV is optimized for its intended mission without unnecessary redesigns.
2. Preventing aircraft damage due to design errors during testing: This is the primary motivation behind the introduction of the "0 loss" concept, which aims to avoid unnecessary damage to the UAV prototypes during the experimental phase.

Since the flight control system is inherently complex, we aim to verify the reliability and mission alignment of the control system through the construction of an LVC environment. This allows us to test and validate the system in a simulated environment, reducing the risks before physical testing begins.

We hope this explanation clarifies the intention behind our methodology and provides additional context for its practical applications.

Thank you again for your valuable suggestions, which have helped us improve the manuscript.

 

Comments 2: [Table 2: What does the title mean?]

Response 2: Thank you for your valuable feedback and constructive comments, which have greatly improved the clarity and readability of our manuscript. I apologize for any inconvenience caused during the review process and appreciate your patience.

In response to your suggestion, we have revised the caption for Table 2 to ensure it more accurately reflects the content and purpose of the table. The updated caption is now:

"Table 2. Technical Parameters for UAVs from Demand Analysis."

We believe this revision significantly enhances the clarity and relevance of the table.

Thank you again for your thoughtful suggestions and helpful guidance, which have greatly contributed to improving the quality of our manuscript.

 

Comments 3: [In figure 10 a) b) c) d) : What does “β” mean?]

Response 3: Thank you for your valuable feedback. I apologize for any confusion caused during the review process and appreciate your patience.

In response to your comment regarding the symbol "β" in Figure 10, we have added its definition (sideslip angle) in Appendix A, Table A, where all the symbols used in the UAV design and simulation are listed. The updated figure caption now refers readers to Appendix A for a clearer explanation.

Angle of attack, sideslip angle

We believe these revisions have significantly improved the clarity of the figure, and we are grateful for your constructive guidance in enhancing the quality of our manuscript.

 

Comments 4: [figure 10 a): the four lines are overlap each other. Please explain it.]

Response 4: Thank you for your constructive feedback. I apologize for any confusion caused during the review process and appreciate your patience.

Regarding Figure 10 a), the overlap in the lines was caused by the large range of the data and the minimal differences between the data points, making it difficult to distinguish the curves. In response, we have applied a zoomed-in approach to better highlight the differences in the data, focusing on the relevant range.

We believe this revision resolves the issue and significantly improves the clarity of the figure.

Thank you again for your helpful suggestions, which have greatly contributed to the improvement of the manuscript.

(a)

 

	0.004	0.14	0.275	0.411	0.549	0.685
	0.003	0.14	0.276	0.412	0.548	0.684
	0.003	0.139	0.275	0.411	0.547	0.682
	0.005	0.141	0.276	0.411	0.546	0.68

 

Comments 5: [In my opinion, aiming to facilitate the understanding of graphics, some explanation of them would be welcome.]

Response 5: Thank you for your constructive comments. I apologize for any confusion caused during the review process and appreciate your helpful suggestions.

In response to your recommendation, we have added the following explanations for Figures 10 and 11:

"As seen in Figure 10(c), the lift-to-drag ratio of DB1 reaches its maximum at an angle of attack of 8°, with a value of approximately 11. Figure 10(d) demonstrates the DB1's ability to maintain stable flight under varying sideslip angles and angles of attack, highlighting its effective lateral control and resistance to crosswind disturbances. Figure 11(a) shows the variation of the DB1 roll moment with respect to different angles of attack and sideslip angles. When the sideslip angle is 0, the roll moment of DB1 changes approximately linearly with the angle of attack, compared to other states. Figures 11(b) and 11(c) illustrate the DB1's excellent stability and recovery capability when subjected to pitching and yawing disturbances, respectively, further confirming its robustness in maintaining stable attitude after disturbance."

We believe these additions enhance the clarity of the manuscript and improve the overall readability of the figures.

Thank you again for your valuable feedback, which has significantly contributed to improving the quality of our manuscript.

 

Comments 6: [Line 308: Aiming to check it so to understand it, it could be Good to include the reference to the figure.]

Response 6: Thank you for your constructive feedback. I apologize for the confusion caused during the review process.

In response to your comment, we have added an explanation of Figure 10 in the manuscript to clarify the relationship between the angle of attack and the lift-to-drag ratio. Specifically, as shown in Figure 10(c), the lift-to-drag ratio of DB1 reaches its maximum at an angle of attack of 8°, with a value of approximately 11. This explanation has been included to provide clearer context for the analysis.

We believe this revision improves the clarity of the manuscript and enhances the reader's understanding of the figure.

Thank you again for your valuable suggestions, which have helped to improve the manuscript.

 

Comments 7: [Line 309: Aiming to check it so to understand it, it could be Good to include the reference to the figure.]

Response 7: Thank you for your constructive comments. I apologize for any confusion caused during the review process and appreciate your understanding.

In response to your suggestion, we have revised the following section for clarity:

"Based on the aerodynamic analysis in Section 3.2, at an angle of attack of 8°, the lift-to-drag ratio is approximately 11, which indicates that the thrust required for steady level flight in a fixed-wing state should exceed 9N when DB1 weighs 10 kg."

We believe this revision enhances the readability of the manuscript.

Thank you again for your valuable suggestions, which have greatly contributed to improving the quality of our work.

 

Comments 8: [Line 328: equations are not readable Line 332.]

Response 8: Thank you for your valuable feedback and constructive comments. I apologize for any confusion caused during the review process and appreciate your patience.

In response to your comment regarding the formatting of Equations 9 and 10, we have reviewed and corrected their alignment and font size to ensure they are displayed clearly and consistently. These revisions improve the presentation of the equations and enhance their readability.

	(8)
	(9)
*sin	(10)

We believe this revision addresses your concern and significantly improves the clarity of the manuscript.

Thank you again for your thoughtful suggestions, which have contributed to enhancing the quality of our work.

 

Comments 9: [typo error. DB1 Line 340:]

Response 9: Thank you for your constructive comments. I apologize for the confusion caused during the review. Due to a writing oversight, "DB10" was mistakenly used instead of "DB1" in Line 340. We have now corrected this error in the manuscript.

Your feedback has greatly improved the manuscript, and we appreciate your careful review and valuable suggestions.

 

Comments 10: [Review title of figure Line 448.]

Response 10: I'm sorry for the trouble I caused you in reviewing the manuscript due to my writing problems. And Thank you for your helpful comment. I apologize for the oversight in the manuscript. As per your suggestion, we have corrected the title of Figure 15 to "Figure 15. DB1 physical prototype".

We appreciate your careful review and valuable feedback, which have greatly contributed to improving the manuscript.

 

Comments 11: [should be figure 19 Line 473:]

Response 11: Thank you for your helpful comment. I apologize for any confusion caused during the review process. We have corrected the reference from Figure 18 to Figure 19 in Line 473, as suggested.

We appreciate your attention to detail and valuable feedback, which have greatly improved the readability of the manuscript.

 

Comments 12: [In air navigation we use altitude with reference to Mean Sea Level (MSL), in my opinion, height should be said instead. Same comment for title of figure 21 Line 496 Figure 22:]

Response 12: Thank you for your constructive comments. I apologize for any confusion caused during the review process and appreciate your understanding and patience.

In response to your comment regarding the use of "altitude," we have updated the manuscript to replace "altitude" with "Height" throughout the text and figures, in line with standard air navigation terminology, where height is referenced relative to Mean Sea Level (MSL). This change has been applied consistently across all relevant sections, including the titles of Figure 21 (b) and Figure 22 (d).

Figure 21 (b)	Figure 22 (d)

We believe this revision significantly enhances the clarity and accuracy of the manuscript.

Thank you again for your valuable feedback, which has greatly contributed to the improvement of our work.

 

Comments 13: [The meaning of the colour bands in the graphs must be indicated, later it is indicated, but it should be said now that this is the first time that these blue/yellow colour codes are used Line 496 Figure 22.]

Response 13: Thank you for your constructive feedback. I apologize for any confusion caused during the review process.

In response, we have added the following explanation to Figure 22 to clarify the meaning of the color bands used in the graph:

Red: Transition state; Yellow: Fixed-wing state; Blue: Multi-rotor state.

We believe this clarification enhances the readability and understanding of the figure.

Thank you again for your valuable suggestions, which have improved the manuscript.

 

Comments 14: [To improve the quality of figure 22 C. The graph that corresponds to each engine is not visible.]

Response 14: Thank you for your valuable feedback. In response to your suggestion, we have revised Figure 22(c) to make the curves more distinct. Specifically, we have used more prominent colors and increased the line width to ensure that each curve is clearly visible and easily distinguishable.

(c)

We believe this revision significantly improves the clarity and readability of the figure.

Thank you again for your careful review and helpful suggestions.

 

Comments 15: [to include “β” symbol and its meaning in the table]

Response 15: Thank you for your thorough review and constructive feedback. I apologize for any confusion caused during the review process and appreciate your understanding and patience.

In response to your suggestion, we have added the symbol "β" (sideslip angle) and its definition to Table A in Appendix A, where all symbols used in the UAV design and simulation are listed.

Angle of attack, sideslip angle

We believe this revision improves the clarity of the manuscript and ensures readers have easy access to the definitions of key terms.

Thank you again for your valuable suggestions, which have greatly contributed to the improvement of the manuscript.

 

Comments 16: [Reference number 24, 50 & 56 are not referenced along the text exposition.]

Response 16: Thank you for your valuable feedback and constructive comments. I apologize for any confusion caused during the review process and appreciate your patience.

In response to your comment:

- Reference 24 and Reference 56: These references were mistakenly included due to a formatting oversight. We have now deleted them and ensured that the citation list is accurate.

- Reference 50: As noted, this reference is correctly cited in Section 4.2.2, line 435. We have double-checked the text to ensure all references are correctly cited.

We have thoroughly reviewed and corrected all references in the manuscript, and we believe these revisions address the issues.

Thank you again for your helpful suggestions, which have greatly contributed to improving the quality of our manuscript.

 

 

Author Response File: Author Response.pdf