Numerical Analysis of Temperature Distribution During Charging Process of Vertically Installed Hydrogen Tanks

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Authors have contributed well the temperature distribution analysis with title “Numerical Analysis of Temperature Distribution During Charging Process of Vertically Installed Hydrogen Tanks”. Some valuable comments are given below;

 

1. The range of governing parameters and potential applications should be included in the abstract section.
2. What method is used to solve the 2D temperature distribution? The methodology is not mentioned in the abstract.
3. What is the behavior of flow? Is flow along the tank or inside the tank?
4. How author used gravity condition during inside flow?
5. The value of all dimensionless parameters is not mentioned in the manuscript. How author solve this model? What are the main characteristics of all parameters?
6. By using buoyancy force, what is the range of buoyancy factor?  

Comments on the Quality of English Language

English quality required minimum improvement.

Author Response

Please refer to the attached response.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

In this work, the Authors presented numerical results of charging tanks positioned vertically within hydrogen transport vehicles. The changes in temperature distribution under different charging environmental conditions (charging time, inlet temperature, ambient temperature, initial temperature, and initial pressure) were analyzed.

 

Detailed remarks:

Eqs. (1)-(6): Not all of the meanings of the symbols used in these equations have been explained in the Nomenclature. It is also worth adding the SI units to all symbols. Some explanations in the Nomenclature are incomprehensible, e.g. beta: coefficient (?), X: design parameter (?), Z: dependent variable (?) and many others.

Eq. (3): This energy equation contains errors. Please check carefully.

Not all initial-boundary conditions for Eqs. (1)-(5) of the mathematical model have been determined. They should be provided in such a way that the reader can independently perform the calculations in his own software to reproduce the simulation results presented in the manuscript. In addition, all values of the parameters used for calculations must be provided.

Also, the regression equations (8)-(11) look interesting, but it is worth showing a comparative/illustrative drawing of these function plots, how these functions fit to the exemplary experimental data.

Due to numerous shortcomings in the mathematical model, it is very difficult for me to interpret the results presented in the numerous figures and tables. Currently, I am unable to verify the correctness of the results.

Author Response

Please refer to the attached response.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This paper is very comprehensive and includes numerous analyses conducted by the authors. However, several fundamental issues need to be addressed before this work can be considered for publication in a scientific journal.

1. The geometry of the problem must be clearly presented (using an illustration), with axes indicating the directions along which the authors analyze heat transport. For example, below Figure 3, it is mentioned that the computational grid used for numerical calculations is shown, but the grid is not actually depicted.

2. The equations being solved must be clearly defined following the problem's geometry. The authors have presented a generalized 3D model using the vector quantity u, but it is not entirely clear which components of u are considered negligible in the 2D axisymmetric geometry.

3. The initial, boundary, and interface conditions (if heterointerfaces are present, as suggested by Figures 2 and 3) must all be explicitly defined.

4. The authors should specify whether they used any commercial software package for their calculations or developed a numerical model themselves. If they developed their model, they should clarify which method was used (finite difference or finite element method) and justify their choice.

5. Each analyzed quantity must be clearly defined. For instance:

   • What is meant by "average temperature"?
   • What is the "maximum temperature" for each region, and how was it calculated?
   • What is meant by the "temperature distribution of the central region"? Along which axis is this spatial distribution considered? What specifically constitutes the "central region"?

6. The methodology for calculating sensitivity must also be explicitly described.

Author Response

Please refer to the attached response.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

First of all, the PDF version of the revised manuscript sent for re-review (compared to the first version) is terribly formatted.
The manuscript contains a lot of strikethroughs, making it difficult to discern what is now the actual content of the work.
Please format your paper carefully according to the journal's guidelines.

Still not all boundary and initial conditions have been explained, and the values of all parameters used in the simulation have not been provided, e.g. G_k, Gamma_k, Y_k in Eq. (4),  G_omega, Gamma_omega, Y_omega, D_omega in Eq. (5) and many other parameters. All data used in the simulation should be provided so that the reader can easily use them to reproduce the simulation results in their own software. From my point of view, the settings of simulations performed in ANSYS may be incorrectly defined by the user, and the results are then obtained from the so-called "black box." and are not always as expected. Therefore, it is important to describe in detail all the dependencies and parameters used in the simulation.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have addressed all of my questions. They revised the manuscript (text and figures) and provided all the necessary information related to the model and the analysis performed based on it. Additionally, they included information about the software used.

I had some difficulty evaluating certain aspects required by the journal because the authors retained illustrations, result figures, and tables from the previous version, marked them as crossed out, and added the revised versions at the end of the manuscript.

 

However, the overall impression is that the paper is suitable for publication in Applied Sciences. I recommend that the authors carefully review the entire manuscript one more time after removing the crossed-out parts and placing the revised illustrations and tables in their respective sections.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf