Analysis of the Thermal–Mechanical–Hydraulic Coordination Mechanism of a Constrained Piston Hydraulic Engine
Round 1
Reviewer 1 Report
The article I reviewed is devoted to the analysis of the mechanism of thermomechanical-hydraulic coordination in a hydraulic motor with a constrained piston. This is an ambitious endeavor that has the potential to contribute to the understanding and optimization of such engines. Unfortunately, despite its thematic value, the presentation and execution of the work leave much to be desired. First of all, the content of the article has an average level. The work contains some valuable information, but it is too poorly integrated to form a coherent whole. Undoubtedly, the authors have a solid knowledge of hydraulic motors, but there is a lack of consistency and clarity in presenting this knowledge. The lack of focus on what is new and innovative in their research means that the reader has a hard time seeing what the authors have actually achieved. The article contains numerous editing and language errors that further complicate comprehension. The work also does not conform to the format that is typical for magazine, which suggests that the authors did not pay attention to editing details. Linguistic errors may be understandable if the authors are not native speakers of the language in which the article is written, but they may disturb readers and make it difficult to understand the material. The lack of citations of mathematical formulas is very disturbing. In a field that is as heavily math-based as fluid mechanics and thermodynamics, such citations are absolutely essential. Without them, readers cannot verify the accuracy of the results or compare them with the results of other studies. The literature review is far too weak. The reader has a right to expect authors to know where their work fits into the broader context of research in their field. Without a solid literature review, the reader has no way of assessing how innovative their work is and how it compares to other research in the field. The conclusions are also imprecise. What is missing is a clear summary of what the authors discovered and what are the implications of their research. For example, the authors suggest that there are some problems with the output flow rate, but do not provide a specific analysis of how these problems can affect engine performance, nor what are the potential solutions to them. Equally troubling is that the authors did not clearly demonstrate what they did themselves versus what is cited from other sources in the methodology and results section. Without such clarity, it is impossible for the reader to appreciate how much of a new contribution this work brings. Authors must indicate which elements of the research are their own contribution and which are the result of the work of others. Despite these problems, the value of the article is its main topic, which is relevant to the field of mechanical engineering. The problem with the effective use of hydraulic and mechanical energy is a real challenge for many types of machines and devices. Solving this problem could bring significant benefits to many industry sectors. I also suggest putting in some publications on the topic calculation methodology: https://doi.org/10.1016/j.energy.2022.126002; https://doi.org/10.4271/2020-01-2227; http://dx.doi.org/10.3390/lubricants7100089’ https://doi.org/10.4271/2006-01-0647.
The main problem is the lack of diligence in language editing. The English language in which the article was written needs improvement. Grammar, stylistic and punctuation errors make it difficult to read and understand. The work does not seem to have been professionally proofread. This is an issue that should be improved to make the text easier to understand and look more professional.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
Originality and Significance Comments:
I have carefully read the manuscript sustainability-2412333 entitled “Analysis of thermal-mechanical-hydraulic coordination mechanism of constrained piston hydraulic engine “. In this work, a mathematical model was proposed to investigate the thermal-mechanical-liquid coupling working process of the single cylinder axial hydraulic engine. Using the proposed model, the conversion mechanism and output of the three types of energy, thermal, mechanical, and liquid, were simulated and analyzed. Several results were presented and discussed, which shows that under the premise of improving the overall efficiency, the constrained piston hydraulic engine can effectively output mechanical hydraulic dual-element power. Additionally, the combustion characteristics and output power performance of the constrained piston hydraulic engine indicators meet the expected design requirements. The manuscript is well written and presented. It is scientifically sound and add to the literature. I have some suggestions:
1. In page 2: Would you please use “… combustion engine, Zhang, T. et al. and Huo et al. proposed the hydraulic restrained …”?
2. In Page 2: Would you please use “Zhang, H. et al. conducted simulation …”?
3. In Page 2: Would you please use “… in multiple fields, Huang established …”?
4. Would you please check shortening several long sentences throughout the manuscript? For example, in Page 2 the sentences include the name of (Zhang Tiezhu) and (Zhang Hongxin0 are long and needs to be shortened (or splitted into 2 or more sentences).
5. Would you please check presenting the figures after its citation (mention) in the main text? Check for example Figure 3.
6. The introduction/literature review/ references’ citation is relevant and up-to- date. Would you please cite more references while presenting and discussing the results?
7. The paper is full of equations and symbols. Would you please check adding (Nomenclature) section before the references’ list??
English technical writing is good and readable. I have to mention that the paper has several long sentences that is preferred to be shortened to improve readability.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
This paper is well-written and presented. I have only minor comments related to general structure and methodology to be considered.
1) The intro sections are a little light. The research gaps, contributions and outline of this paper are not sufficiently clear. I recommend developing the introduction along the following path.
· Explore other related works and analyze their contributions (what has been done?), their limits (what has not been done?).
· List those limitations that are the major research gaps on this topic.
· Bring and list your contributions.
· When completed, a paragraph describing the methodology of this work, the main objectives and the sections is needed to draw a map for readers to follow when reading the paper. Because the current representation does not communicate clearly as we do not know what will come next and why.
2) Likewise, for each new section of the paper, it is best to insert a brief paragraph describing the main content, purpose and structure of that section to ensure that readers are inline with the flow.
3) Figure 2 is difficult to follow because the beginning and end of the working process are not given. I recommend adding such information.
4) It is not encouraged to number conclusions.
5) Try to simplify representation of figure 3 as their similar parts there with only few differences. Please merge them and provide an optimized and easy to understand flow diagram.
6) Figure 9 is a little described. Besides, some colors and shapes in legend require further descriptions and details. This comment is applied on all figures to be further described.
Author Response
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Author Response File: Author Response.pdf
Reviewer 4 Report
The research focuses on the integration of traditional engines with reciprocating plunger pumps to create a constrained piston hydraulic engine. This engine simultaneously outputs hydraulic energy and rotational mechanical energy, addressing issues related to complex structure, long power transmission chains, and low energy conversion efficiency. A single-cylinder axial constrained piston hydraulic engine is designed based on a diesel engine, and its thermal-mechanical-liquid coordination mechanism is extensively studied. A mathematical model is developed to analyze the thermal-mechanical-liquid coupling working process, simulating and analyzing the conversion and output of thermal, mechanical, and liquid energy.
Academic questions:
- How does the constrained piston hydraulic engine address the issues of complex structure, long power transmission chains, and low energy conversion efficiency compared to traditional power sources?
- What are the key design considerations and challenges in developing a single-cylinder axial constrained piston hydraulic engine based on a diesel engine?
- How does the thermal-mechanical-liquid coordination mechanism contribute to the overall efficiency and performance of the constrained piston hydraulic engine?
- What specific methods can be employed to effectively suppress flow rate pulsation and ensure reliable output flow rate in the constrained piston hydraulic engine?
- Are there any limitations or potential drawbacks of the constrained piston hydraulic engine that need to be addressed in further research?
Potential academic limitations and suggestions:
Validation of Models: While the study establishes various models for the hydraulic engine, further validation is necessary to ensure their accuracy and reliability. Conducting experimental tests or comparing the simulation results with real-world data would enhance the confidence in the models' predictive capabilities.
Sensitivity Analysis: Performing sensitivity analyses on the model parameters would provide insights into the impact of variations in parameters on the performance of the hydraulic engine. This analysis can help identify critical parameters and optimize the engine's design and operation.
Leakage and Reflux Mitigation: Addressing the issues of hydraulic oil leakage and reflux causing negative values in the discharge valve's output flow rate is crucial. Investigating the causes of these issues and proposing effective solutions, such as improved sealing mechanisms or fluid control strategies, would enhance the reliability and efficiency of the hydraulic engine.
Flow Rate Pulsation Suppression: The study acknowledges the significant fluctuations in the output flow rate of the hydraulic engine. It would be valuable to explore different methods and techniques to mitigate flow rate pulsations, such as employing damping devices, optimizing system components, or implementing advanced control algorithms.
Comparative Analysis: To assess the advantages and limitations of the proposed constrained piston hydraulic engine, a comparative analysis with other existing hydraulic engines or traditional power sources could be conducted. This analysis would provide a broader perspective on the performance, efficiency, and practicality of the proposed engine and help position it within the existing literature and industrial applications.
Generalizability and Scalability: The study focuses on a specific hydraulic engine configuration and output power. Assessing the generalizability and scalability of the proposed approach to different engine sizes, power requirements, and applications would expand its applicability and provide a more comprehensive understanding of its potential.
Long-term Reliability and Maintenance: Considering the complex nature of hydraulic systems, investigating the long-term reliability and maintenance requirements of the proposed engine is essential. Analyzing factors such as component wear, fluid degradation, and maintenance intervals would provide insights into the engine's durability and operational sustainability.
The English of the paper is recommended to find professionals for further polishing.
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors include all my comments
Author Response
Dear Reviewer,
I would like to express my heartfelt gratitude for your diligent review and valuable suggestions on my manuscript. Your expertise and meticulous evaluation have been immensely valuable to me.
I sincerely appreciate your support and affirmation of my research. Your guidance has been invaluable in improving the quality of my study and paper.
Once again, I want to convey my deep appreciation for your time and effort. If there are any further questions or opportunities for collaboration, please feel free to contact me.
Thank you once again for your dedication and support!
Reviewer 4 Report
The academic aspect and revised content have reached the publishing level, and can be considered for acceptance by the editor.
Further language modifications are needed to meet the needs of the journal.
Author Response
Dear Reviewer,
I would like to express my heartfelt gratitude for reviewing my manuscript and providing valuable comments and suggestions. I truly appreciate your support and encouragement regarding my paper.
Based on your suggestions, I have made further improvements to the language of the article to enhance its accuracy and fluency. Your guidance has been immensely helpful to me, and I will continue to strive towards improving my writing skills.
Once again, I want to thank you for your reviewing work and valuable feedback. Your expertise and experience are highly valuable to me.
Thank you once again for your efforts and valuable insights.
