Flutter Characteristics of a Modified Z-Shaped Folding Wing Using a New Non-Intrusive Model

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper presents an interesting discussion on the effects of the modeling parameters for the folding wing in question. Section 3 was very clearly presented and the effort to present a detailed text is appreciated. The main discussion and conclusions points are related to structural components (stiffness and damping parameters) rather than aerodynamic parameters, so one suggestion would be a small modification in the title to account for that; as it is now, the title led me to expect something different for the discussion than what was presented.

While reading Section 4 and its subsections, a few questions came up during the review, and they were answered by something said later in the text. So, one suggestion is to connect the discussion items when appropriate, even if they are not in the same location in the text:

- Sentence 298 – how many modes were considered in the solution? Have you made a modal convergence analysis to see if there is participation of higher modes? What types of modes? Bending, torsion, mixed? It would be good to have a picture with the first 6 mode shapes (for the initial model you are considering) to help with visualization and a better understanding of the analysis. For example, there is an analysis of the number of modes in line 302, but still no information about what the mode shapes look like. Suggestion: present this analysis before you make the statement on line 298, to facilitate the analysis.

- Subsection 4.1: It would be interesting to have the analysis of the hinge stiffness effect on the flutter boundary, and how much it affects the aeroelastic damping in the system. For example, there is a similar analysis in subsection 4.2. Suggestion: add a connection between the two discussions.

Comments on the Quality of English Language

Additional comments:

- Sentence in line 32 – seems a little confused. Suggest rewrite.

- Sentence in line 226 – shouldn’t it be Figs 3 and 4?

Author Response

Please see the attachment.

Author Response File: Author Response.doc

Reviewer 2 Report

Comments and Suggestions for Authors

This manuscript analyses the flutter behavior of Z-shaped folding wings. The manuscript topic is relevant and the presented results support the conclusions. However, some major points should be addressed before publishing this work in an archival journal.

Some specific comments:

1) Can you better describe the Double Lattice Method you employ in the analyses? That includes the equations being solved and the assumptions made.

2) I think the paper would benefit from comparing the flutter characteristics of the original and modified wings.

3) The description of Figures 3 and 4 are vague. Figure 3 should be the discretization of the finite element model and the description of Figure 4 should be rewritten. "This is a figure. Schemes follow the same formatting." this does not mean anything to the reader.

Author Response

Please see the attachment.

Author Response File: Author Response.doc

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The authors addressed all the relevant comments in the previous review and the manuscript is suitable for publication in its present form.