Analysis of Longitudinal Braking Stability of Lightweight Liquid Storage Mini-Track Vehicles
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe paper addresses a topic of interest for the applications, i.e., the longitudinal braking stability (LBS) for a liquid-storage track vehicle. The influence of characteristics parameters of the system on the LBS are studied via FEM simulations. Finally, by combining simulation and experimental results, the track vehicle parameters that satisfy the LBS are obtained. The paper is well written but it’s organization can be improved.
First of all, I suggest to put at the end of the first section (Introduction) a paragraph that recalls the content of the sections that follow, e.g.: “The outline of the paper is as follow. Section 2 presents the LBS model, etc. etc. Section 3 shows the simulation results etc. etc. Section 4 etc. etc.”.
I also suggest to modify all the figures captions. Specifically, in Figure 1, I would include the figure description “1.Guide wheel; 2. Tension buffer device; …” directly within the caption (e.g., “Three-dimensional model of the chassis of the track vehicle: 1.Guide wheel; 2. Tension buffer device; …”). The same applies to the other figures.
All equations should be centered in the same manner (see, e.g., Figure 5, it is not centered as Figure 4; see also Figure 7, Figure 10, Figure 13, Figure 15).
For what concerns Figures 17 and 19, it should be better organized, together with their captions.
Moreover, all equations should be justified on the right in the same manner. See, e.g., equations (10) and (9).
Please read and correct the commas at the third line after Figure 13. Moreover, please consider leaving some space between figures and text, i.e., above and after any figure.
Finally, in the “Conclusion” section I suggest to better specify which the novelty of the present work is.
Author Response
Comments 1: First of all, I suggest to put at the end of the first section (Introduction) a paragraph that recalls the content of the sections that follow, e.g.: “The outline of the paper is as follow. Section 2 presents the LBS model, etc. etc. Section 3 shows the simulation results etc. etc. Section 4 etc. etc.”.
Response 1: Agree. A paragraph that recalls the content of the sections has been added, that is, “The outline of the paper is as follow. Section 2 presents the LBS model, etc. etc. Section 3 shows the simulation results. Section 4 list the road experiment. Section 5 is the conclusion.”
Comments 2: I also suggest to modify all the figures captions. Specifically, in Figure 1, I would include the figure description “1.Guide wheel; 2. Tension buffer device; …” directly within the caption (e.g., “Three-dimensional model of the chassis of the track vehicle: 1.Guide wheel; 2. Tension buffer device; …”). The same applies to the other figures.
Response 2: Agree. All the figures captions have been modified according to your suggestion.
Comments 3: All equations should be centered in the same manner (see, e.g., Figure 5, it is not centered as Figure 4; see also Figure 7, Figure 10, Figure 13, Figure 15).
Response 3: Agree. All equations have be centered in the same manner according to your suggestion.
Comments 4: For what concerns Figures 17 and 19, it should be better organized, together with their captions.
Response 4: Agree. Figures 17 and 19 have been modified according to your suggestion.
Comments 5: Moreover, all equations should be justified on the right in the same manner. See, e.g., equations (10) and (9).
Response 5: Agree. All equations have be justified on the right in the same manner according to your suggestion.
Comments 6: Please read and correct the commas at the third line after Figure 13. Moreover, please consider leaving some space between figures and text, i.e., above and after any figure.
Response 6: Agree. The commas at the third line after Figure 13 has been corrected, and some space between figures and text have been left.
Comments 7: Finally, in the “Conclusion” section I suggest to better specify which the novelty of the present work is.
Response 7: Agree. The “Conclusion” section has been enriched, “The track vehicle works at the complex and narrow disaster site, so it was important and innovative to study its braking stability in this paper. And the fluid-structure coupling analysis of oil, fuel tank and track vehicle was carried out when analyzing the longitudinal stability of track vehicle” has been added.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsDear Authors,
Your article presents an interesting simulation, supported by experimental research. To increase the quality of your article, I recommend making the following changes to the article:
I recommend stating more clearly:
• What is the expected density of the liquid?
• What is the weight of the vehicle? What is the mass of the liquid?
• How was the position of the vehicle's center of gravity determined?
I recommend comparing your results with those of other authors.
Sincerely
Reviewer
Author Response
Comments 1: What is the expected density of the liquid?
Response 1: Description of density is at the ten line after Figure 6. “The hydraulic oil had a density of 876 kg·/m3 and a viscosity of 0.048 kg·/(m·s) ”.
Comments 2: What is the weight of the vehicle? What is the mass of the liquid?
Response 2: The body weight is 500 kg when unloaded, and the total body weight is 700 kg when loaded.
The mass of the liquid depends on the liquid-filling ratio (TLR), which is 0.5,0.6,0.7,0.8,0.9 respectively. The total tank volume is 80 L. It is specifically equal to the corresponding proportional volume of liquid multiplied by the density.
Comments 3: How was the position of the vehicle's center of gravity determined?
Response 3: Basing on the mass and spatial distribution of the components of the track vehicle, the components were modeled by Solidworks software and the material was assigned to determine the centroid position of the different components. Then the center position of the track vehicle can be calculated by the moment balance formula.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThank you for submitting the manuscript titled "Analysis of Longitudinal Braking Stability of Liquid-storage Lightweight-mini Track Vehicle" for review. The study of the influence of tank liquid-filling ratio, initial velocity, and initial braking deceleration on the Longitudinal Braking Stability (LBS) of the tracked vehicle presents valuable insights.
While the paper is well-organized and the explanation commendable, significant revisions are necessary to meet publication standards. There are numerous typographical errors, inaccuracies, and areas needing language improvement. I have outlined specific corrections below to assist with the revision:
1. There is a discrepancy between the methods cited in the abstract and those used in the manuscript. The abstract mentions the Finite Element method, whereas the paper specifies the use of ANSYS Fluent software, which employs the Finite Volume method for fluid problems. Please clarify this in the abstract.
2. Remove "Finite Element" from the keywords to avoid further confusion.
3. Figure 3 does not align with the equations presented. Please amend ay​ to ax​ in the figure to correct this inconsistency.
4. Revise Equation (1) to F_x=(m_z)( a_x)​, and adjust all y subscripts to x throughout the text and equations, specifically Equations (2) and (4).
5. On Page 3, before Equation (4), the reference to Equation (13) should be corrected to Equation (3).
6. Equation (5) on the right-hand side appears incomplete and lacks a_x​. Please revise accordingly.
7. In subsection 3.1. Explain more how you convert the liquid tank from 3D into 2D
8. Correct the equation (7)
9. In Equation (8), change u, v, and w to u_1,u_2 and u_3 respectively, and F_x​ to Fi. If describing the momentum equation in the x direction, u_i​ should be changed to u1​.
10. In Equation (9) define all the constants and variables.
11. The numerical results presented lack verification and validation, crucial for establishing the reliability of the findings. The authors have included only one comparable experimental figure, Figure 18, which does not directly correspond with the numerical results. It would be beneficial to normalize the values in the figure to enable a meaningful comparison.
The manuscript currently lacks the precision and accuracy required for scholarly publications. I strongly recommend a comprehensive revision to address the issues noted above, as well as any additional typographical errors not explicitly mentioned.
Author Response
Comments 1: There is a discrepancy between the methods cited in the abstract and those used in the manuscript. The abstract mentions the Finite Element method, whereas the paper specifies the use of ANSYS Fluent software, which employs the Finite Volume method for fluid problems. Please clarify this in the abstract.
Response 1: I have unified the research methods of this paper. The “Finite Element method”in the abstract has been modified for “Fluent simulation”. I confirm that there is no description of "finite volume method" in the paper. In the paper，Chen [10] established a numerical calculation model of liquid slosh based on the finite volume method for the studied vehicle liquid tank，but that's not the simulation approach I take.
Comments 2: Remove "Finite Element" from the keywords to avoid further confusion.
Response 2: Thank you very much. The “Finite Element method ” in the keywords has been modified for “Fluent simulation”.
Comments 3: Figure 3 does not align with the equations presented. Please amend ay to ax in the figure to correct this inconsistency.
Response 3: The “ay ” has been amend to “ax” in the Figure 3. Equation 1 and 4 were also modified accordingly.
Comments 4: Revise Equation (1) to Fx=(mz)(ax)​, and adjust all y subscripts to x throughout the text and equations, specifically Equations (2) and (4).
Response 4: Accordingly y subscripts have been adjusted to x in Equation 1,2 and 4, also the corresponding text.
Comments 5: On Page 3, before Equation (4), the reference to Equation (13) should be corrected to Equation (3).
Response 5: Agree. Equation (13) has be corrected to Equation (3).
Comments 6: Equation (5) on the right-hand side appears incomplete and lacks ax​. Please revise accordingly.
Response 6: Agree. Accordingly ax in Equation (5) has been added.
Comments 7: In subsection 3.1. Explain more how you convert the liquid tank from 3D into 2D
Response 7: The fuel tank is a regular cuboid, which belongs to the flow problem of equal cross section area. Moreover, our research goal is the longitudinal stability of the tracked vehicle, so the influence of the lateral wall of the tank on the oil flow field distribution is ignored. The three dimensional model of oil is simplified to two dimensional model in longitudinal direction.
Comments 8: Correct the equation (7).
Response 8: Equation (7) has been modified in the revised paper.
Comments 9: In Equation (8), change u, v, and w to u1, u2 and u3respectively, and Fx to Fi. If describing the momentum equation in the x direction, ui should be changed to u1.
Response 9: Equation (8) has been modified in the revised paper.
Comments 10: In Equation (9) define all the constants and variables.
Response 10: All the constants and variables in equation (9) has been added in the revised paper.
Comments 11: The numerical results presented lack verification and validation, crucial for establishing the reliability of the findings. The authors have included only one comparable experimental figure, Figure 18, which does not directly correspond with the numerical results. It would be beneficial to normalize the values in the figure to enable a meaningful comparison.
Response 11: In the paper the influence of tank liquid-filling ratio (TLR), initial velocity (IV), and initial braking deceleration (IBD) on the LBS of the tracked vehicle was studied via the FLUENT simulation.
When the TLR was 0.7, the maximum longitudinal impact force was 504.5 N, the braking efficiency decreased by 32%, and these results were close to those obtained with an initial velocity of 5 km/h, which was within the acceptable range of reduced braking stability. In order to ensure the work continuity of the track vehicle outdoors, the TLR should be set as large as possible. There are many parts of the tracked vehicle, and there are too many interfering factors when testing the influence of initial braking deceleration on longitudinal stability. For example, excessive initial brake deceleration will lead to vibration superposition of the motor, gearbox, pump and other components of the tracked vehicle itself, greatly affecting the experimental results. Therefore, we only conducted experimental tests on the effect of initial IV on the LBS of the tracked vehicle.
Comparing Figure 11 in the numerical results and Figure 18 in the experimental figures, we find that the average effective braking deceleration (AEBD) of the two figures are very close, that is, 2.5~3 m/s2. The effective braking deceleration changes with time, so it is not significant to do numerical normalization.
Author Response File: Author Response.pdf
