Dynamics Modeling and Motion Evaluation of a Near-Ground Tethered Balloon Cable System under Severe Wind Environments
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsI have carefully reviewed the dynamics modeling and motion evaluation of a near-ground tethered balloon cable system under severe wind environments. This study presents a novel approach to modeling near-ground tethered balloon systems, examines the dynamic responses of the system, and evaluates the effects of varying the number of tethered cable segments, the location of external wind loads, and the influence of lateral winds on the balloon. The research is innovative and suitable for publication in this journal. However, some modifications are required to make this paper acceptable for publication.
1 It would be beneficial to provide detailed wind speed time histories and specify the loading positions for the various cases. The current descriptions of the cases in the manuscript are overly simplistic, making it difficult to conduct a thorough comparison.
2 Figure 7 presents the aerodynamic force coefficients corresponding to lift, drag, and pitch moment. However, it is unclear to which object these coefficients pertain, which may lead to confusion. Additionally, the manuscript would benefit from a clear definition and illustration of the pitch, yaw, and roll angles for the discrete rigid bodies discussed.
3 The dynamic response of the tethered balloon is calculated based on a mean wind profile, which does not account for the turbulence intensity present in real-world wind environments. This omission could significantly impact the accuracy and reliability of the results, potentially making the conclusions of this study less convincing. To enhance the credibility of the findings, it is recommended to consider the effects of turbulence in the analysis.
4 Figure 10 presents the pressure distribution on the surface of the tethered balloon under the specified conditions. However, this figure appears to be unrelated to the main focus of the study and may not contribute meaningfully to the overall analysis.
5 In Section 4.4, the dynamic responses under wind profiles are discussed, with the postures of the tethered balloon system described in terms of pitch, yaw, and roll angles. However, the following results are presented in terms of the three phases of the tethered balloon, which creates a disconnect in the organization of this section. To enhance clarity, this part should be better structured, ensuring consistency between the description of the system's postures and the presentation of the results.
6 The paper should be thoroughly reviewed for spelling and clarity in descriptions. For instance, phrases like 'Figure 18 shows that the yaw Angle and roll Angle still fluctuate around 0° when the gust deflection angle is 10°' require correction and refinement."
Comments for author File: 
Comments.pdf
Minor editing in English is required.
Author Response
Please kindly see the attached RESPONSES TO REVIEWERS.
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe manuscript introduces an approach for modeling the dynamic behavior of near-ground tethered balloon systems, which are challenged by the flexible nature of their cables and the complex forces from wind gusts. The proposed method models the tethered cable as a series of finite cylindrical rigid bodies connected by bushing forces, allowing the simulation of the cable's flexibility under severe conditions. By integrating multibody dynamics theory, the study investigates the dynamic responses of the tethered balloon system under varying wind conditions and other environmental factors. The research highlights the significant impact of cable load, segment discretization, and wind direction on the system's stability and performance. The model demonstrates a considerable improvement in solution time over traditional CFD methods, with minimal pitch angle deviation, making it a more efficient tool for performance evaluation. The findings emphasize the importance of considering cable load and wind effects in the design of tethered balloon systems, suggesting that the proposed model could enhance the system's stability and performance in challenging weather conditions. The topic is interesting, and the paper is well prepared. However, the reviewer has some concerns regarding the paper's contributions and application in this manuscript, so this manuscript is not ready for publication in its current form.
Here are some questions and comments:
ü In the introduction section, the literature review should be more detailed and comprehensive. Authors should incorporate recent research developments into this part and provide a brief overview of the historical development of the topic.
ü It would be beneficial for the authors to clarify their study's objectives and novelties in the Introduction section in more detail.
ü The manuscript contains numerous grammatical mistakes throughout. It is strongly recommended that the authors thoroughly review and edit the entire manuscript for these errors.
ü The authors should explain the advantages of their proposed method over other recently published methods. They need to provide a comparative analysis with another recent method to demonstrate its efficiency.
ü In addition to comparing different parts of their modeling the dynamic behavior of near-ground tethered balloon systems with others, the authors should clearly highlight the conceptual advantages of their scheme. Emphasize the novelty of their manuscript, which revolves around their proposed control strategy.
ü The quality of the figures in the paper, especially figures 2, 3, 11 and 16-18, is notably low. The authors should work on enhancing the figure quality throughout the manuscript.
ü Provide more detailed explanations for the results presented in figures 8, 12, 14, and 15.
ü It is essential that the parameters used in the manuscript are clearly defined. The authors should consistently address this issue throughout the manuscript. Additionally, ensure that all parameter values are included when presenting numerical results.
However, I have a couple of concerns regarding the manuscript. The novelty of the work seems questionable in light of already published papers. Additionally, the comparison presented is not acceptable because the method should be compared with recent approaches, not just traditional schemes. Comments on the Quality of English Language
The manuscript contains numerous grammatical mistakes throughout. It is strongly recommended that the authors thoroughly review and edit the entire manuscript for these errors.
Author Response
Please kindly see the attached RESPONSES TO REVIEWERS.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsI) At the end of the abstract, briefly introduce some concrete results.
II) Instead of "Weather surviving" write "Weather survival", in line 1.
III) Write "utilisation" as "utilization", in line 1.
IV) Instead of "system overall performance" in line 11, put "system's overall performance".
V) The statements in lines 134-138 require supporting citations.
The deformations are not taken into account, and the discretized cable segments are all viewed as rigid bodies. In order to approximate the flexibility of the entire wire system, we employ a huge number of stiff bodies. The substance of cable is uniform and predetermined to be of one kind. To prevent the balloon and cable portions from separating, a ball-hinge pair is added at the point where the top end of the cable meets the balloon.
VI) The statement in lines 138-140 does not correspond to the drawing in Figure 2, so the reader of your work will have to imagine the promised 12 cables, because they do not come out when counting.
As illustrated in Fig. 2, the 12 cables that make up a funnel in cable system end are aggregated together, and this connection is made by a spherical joint. A ball hinge pair connects the near-ground end of cable to the ground.
VII) In lines 138-140, the word non-articulated cable appears twice, so insert the article the cable.
VIII) Please discuss in more detail the bushings (presented in Figure 1) and explain their advantages and disadvantages compared to the classic Spherical joints.
IX) Put "The diameter and the length of every Rb is expressed as Lt and Dt , respectively" from line 146 in the correct form:
"The diameter and the length of every Rb is expressed as Dt and Lt, respectively".
X) Discuss the results presented in Figure 7 in more detail.
XI) Discuss the results presented in Figure 8 in more detail.
XII) Discuss the results presented in Figure 10 in more detail.
XIII) Insistati in section 5, Discussion, about how the number of discrete stiff bodies affects the responses of the system.
I) Instead of "Weather surviving" write "Weather survival", in line 1.
II) Write "utilisation" as "utilization", in line 1.
III) Instead of "system overall performance" in line 11, put "system's overall performance".
IV) In lines 138-140, the word non-articulated cable appears twice, so insert the article the cable.
Author Response
Please kindly see the attached RESPONSES TO REVIEWERS.
Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for Authorssee attached file
Comments for author File: Comments.pdf
Comments on the quality of English language are reported in the attached document
Author Response
Please kindly see the attached RESPONSES TO REVIEWERS.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThe revised paper has been improved. However, I still have some minor comments on this manuscript as follows:
- The format of references should be improved according to the Journal style.
- In the conclusion section, the authors are suggested to add some potential future works about your current work.
- Please check the paper's writing mistakes carefully.
- Please check the paper's writing mistakes carefully.
Author Response
Please kindly see the attached "RESPONSES TO REVIEWERS V2".
Author Response File: Author Response.pdf
