An Adaptation of Nonlinear Aerodynamic Models for Non-Traditional Control Effectors^†

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper fits the journal's scope. The iThenticate check shows a 44% similarity index, and the main contributor is: “Aerodynamic Implications of a Bio‐Inspired Rotating Empennage Design for Control of a Fighter Aircraft”, which is a PhD thesis of the corresponding author. In my opinion, this value is too high and thus, the author should modify the text. Besides that, I enjoyed reviewing this manuscript and have a few comments that the authors should respond to:

- Present definitions of \bar{p}, \bar{q} and \bar{r} to specify reference dimensions for nondimensional angular rates.

- Can the authors present the accuracy of the least squares fit for individual sensitivity parameters vs empennage rotation?

- "Details on how the baseline aircraft coefficients were produced are included on Boolander [21]" – please add a short information about this procedure in the manuscript.

- Can the authors provide a quantitative measure of the BIRE fit for the data presented in Figs. 2-7? This should be accompanied by a brief discussion on the accuracy of the outcomes.

I recommend a major revision.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The study is generally very well structured and presented. However, the following recommendations are presented for readers to better understand the study.

*The results given with graphs could have been explained by relating them better to the purpose of the study.

*The contribution of the study could have been more explanatory in comparison with the traditional situation.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

This paper describes development of an aerodynamic model tailored for the Bio-Inspired Rotating Empennage (BIRE), a non-traditional fixed-wing aircraft empennage inspired by avian flight. The BIRE replaces the conventional vertical stabilizer with an extra degree of freedom for the horizontal stabilizer, which is allowed to rotate about the body-fixed x axis. This empennage is similar to the tail of a bird and allows control of both longitudinal and lateral moments. However, such a design introduces complex nonlinear longitudinal and lateral aerodynamic interactions, not typically accounted for in most fixed-wing aircraft aerodynamic models below stall.

Strengths of this paper: The paper describes a new trend in aerodynamic modeling approach for a non-traditional control system. In addition, some simulation results are shown to evaluate it.

Weaknesses of the paper: There is a lack of illustrative figures and an insufficient description of the equations used. This makes it challenging for readers to follow the paper and understand its concepts.

The following points should be considered:

1-The abstract should include a summary of the key results, such as the mean error, to provide a clearer understanding for readers.
2-The References must be carefully reviewed and updated.

3-The authors should add a clear figure to section 2. “A Traditional Non-Linear Aerodynamic Model” to visually represent the model and its key parameters.

4-In section 2 and 3 there is a lack of clear definitions for several parameters and constants used in equations. Providing explicit definitions and explanations would improve clarity and help readers follow the paper more effectively.

5-Figure 1 is unclear and would benefit from additional labels to improve its readability.

6- The author did not add any value in the abstract and the conclusion that demonstrates the effectiveness of the work.

7-The result needs to be compared with previous work in this field.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for providing the updated version

Author Response

Thank you for your help in improving this work.

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have done a good job in updating the paper and almost have  reply to all of my previous comments. However, my main concern is that most of the references are too old. This gives the impression that the work does not reflect the current state of the art. I strongly recommend that the authors revise the manuscript to include more recent references and incorporate developments from the latest research and technologies in this field.

Author Response

Comments 1: However, my main concern is that most of the references are too old. This gives the impression that the work does not reflect the current state of the art. I strongly recommend that the authors revise the manuscript to include more recent references and incorporate developments from the latest research and technologies in this field.

Response 1: The authors understand the concerns of the reviewer and have updated the manuscript with 9 additional references (Refs. 16-21 and 25-27) highlighting more recent additions to this field. These more recent studies still fit within the general paradigms that the authors outlined in their introduction to the work; however, emphasis is given to the role of system identification in lines 48-49, and the relationship between the present work and the state of the art is given explicitly by two additional sentences in lines 50-54.

 

Thank you for your additional time to help us improve this paper.