A Review of Icing Research and Development of Icing Mitigation Techniques for Fixed-Wing UAVs

Round 1

Reviewer 1 Report

This paper is a review paper on icing research for Fixed-wing UAVs. The paper is well written and comprehensive and worth of publication. It would have been interesting to combine the rotating wing as well. The biggest issue with the paper is the lack of references from great Canadian authors on the subject like Villeneuve, Samad, Orchard, Momen. In addition, I also have the following comments :

Line 27: First sentence not necessary.

Line 39: Should add Delivery as well.

Line 65: Should add Canada.

Line 81: could mention the effect of lower speeds on collection efficiency.

Line 380 : The weight of the fluid is also a deal breaker.

Line 387 to 392 : References should be added to the text (there are many examples of study for this, even on UAV).

Line 400: Difference between anti-icing and de-icing.

Section 4 is missing mechanical ice protection system and vibration based systems.

Line 486: This is not as much of a concern for smaller drones (especially if you can reapply often).

Section 5.3 is missing icephobic coatings and adhesion reduction.

Section 5.5 misses many references on the subject, especially on resonance mode (Villeneuve, Palanque, Budinger, etc).

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

This manuscript reviewed the icing problem and the research progress for fixed-wing UAVs. The experimental and numerical methods were summarized from the traditional manned aircraft to the UAVs, and the difference was presented and analyzed. In addition, the classical ice protection methods were studied and compared with the requirement of the UAVs. This review is helpful for the icing theory and the design of the UAVs. A minor revision was required before publication.

1. "These existing icing simulation tools validated for manned aviation at high Reynolds numbers [21] cannot be directly applied to simulate UAV icing at low Reynolds numbers." What is the main difference between the manned aviation and the UAV? Only Reynolds numbers? Since there are many studied for different components of the manned aviation, the Reynolds numbers range is quite large and most icing simulation codes have been verified, especially for the tests in icing tunnel with low velocities.

2. What are the icing models used in Section 3.1? Are they developed for the conditions with low Reynolds numbers?

3. Delete Section 0.

4. Check the language format

5. Discussions and Conclusions could be better summarized.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The work provides a comprehensive overview of research on fixed-wing icing in unmanned aerial vehicles. The topics are adequately researched in manned civil aviation. The unmanned aircraft market is just developing intensively and requires properly conducted research for drones, which can have very different characteristics. I believe the review was conducted soundly and the conclusions drawn correctly. However, I miss a tabular summary, which will be very useful for readers. 

Minor editorial corrections may be made to the work in writing.

Author Response

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Author Response File: Author Response.pdf