Numerical Computation and Analysis of Electromagnetic Field in Magnetic Suspension and Balance System

Round 1

Reviewer 1 Report

It is a well-written paper and can be considered for the publication after minor revision. 

• Abstract: Abstract should be very simple and short with the review gap area, which is emerging and need of the hour.
• English needs to be further sharpened as there few mistakes and sentences constructed with bad words. Please revise the paper carefully with the help of a native English speaker.
• INTRODUCTION: This section is well written and can further reduce by citing suitably with the published publication.
• Introduction: Please revise the content with three main areas such as the importance of this study, literature available and current methodology with innovative step adopted.

• The conclusion looks like a discussion point. Please revise the conclusion with a summary of the crisp findings with values.
• The author should summarize the findings and also mention how it can be useful in the real-time situation.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

In this manuscript, the authors utilized FEM modelling to numerically analyze and demonstrate the electromagnetic field in magnetic suspension wind tunnel balance. It is shown that compared to the typical wind tunnel balance, the proposed approach provides a promising mechanism to deal with airflow interference. Beyond that, it is claimed that using the developed approach, the aerodynamic measurement environment would be more authentic and the aerodynamic measurement results are more precise. This was realized by studying the axial coil of the high subsonic magnetic suspension wind tunnel balance. Although the work contains interesting results, it needs for addressing some unclear points. I listed my concerns below and suggest the authors to revise their work by addressing the comments. 

General comments:

1) The quality of illustrations and images are too low and it is quite difficult to understand the physics of the work. All graphs and specifically Figure 4 must be comprehensively updated.

2) The writing quality of the work must be improved and polished carefully. In addition, the acronyms (e.g., FEM) must be provided in a correct place.

3) What type of finite element software was employed? If any commercial program was used, then it must be declared, cited, and the details must be provided comprehensively.

4) The use of magnetic loop current in other fields such as photonics must be mentioned in the bibliography part of the manuscript, such toroidal magnetic loop currents (Photonics 6(2), 43 (2019) and The Journal of Physical Chemistry C 122(42), 24304–24308 (2018)).

Technical comments:

5) It is mentioned that "The larger the pitch angle is, the smaller the
electromagnetic force is". However, in the plotted graph (Figure 9), the difference is not significant. This must be explained.

6) The accuracy of the developed model must be compared with analogous ones in the literature.

7) It must be discussed that how the platform operates in real experiments and practical assays.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

The authors present a novel way of suspending wind tunnel models in the freestream through elctromagnetic forces instead of using a rigid support system and have provided a proof of concept numerical investigation showing the influence of various parameters.

It is understood that the work does not have currently any experimental data available which would be of great use and that such a prototype is currently under consideration / production (?!). At this point, it may be best to concentrate a bit more on the feasibility aspects; for example, if we remove the rigid support system and rely entirly on electromagnetic forces, what influence does that have on the stability of the model under test, i.e. is the level of oscillation acceptable? (This question may be answered by linking an appropriate reference from the literature here).

However, there are some other data that can be derived from the results presented, for example, what is the additional electricity consumption compared to the electricity required to run the wind tunnel itself? And how does that scale with model size (weight)? These would be interesting numbers to show so as to get a better idea of what can be achieved with this technology and at what cost.

Otherwise, clarity is sometimes missing and it requires several reads to understand what is done. For example, Section 3 (when talking about the numerical model and setup), it is not immediately clear what is exactly modelled and how. This may be an area the authors wish to make more clear, otherwise, this paper presents a good contribution to an interesting new research field.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The comments and concerns have been responded correctly. Therefore, the work is publishable as is.