Assessment of the Dynamics Flow Field of Port Plate Pair of an Axial Piston Pump
Round 1
Reviewer 1 Report
Dear Authors,
My comments on your article are in the attached file.
Comments for author File: 
Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 2 Report
General comments:
The paper investigated the flow evaluation process in the single piston-valve pump. Both numerical and experimental methods are applied in the flow assessment. It can turn out to be a good paper if the research work is better clarified and the writing is better organized. However, the current presence of the manuscript needs a major revision considering the following detailed comments.
There are quite a few typos and in the manuscript. Please check the manuscript carefully and refine the language.
I list some of them in the following, but more can be found in the manuscript.
Line 18: verify à verifies
Line 23: reduce-à be reduced
Line 34: , this will -à , which will
Line 325: delete ‘international advanced’
The font size is not consistent. The font size in the equations and the variables in the text are larger than that of the normal text.
The meaning of the title seems not very clear.
Do the authors want to say ‘assessment of the dynamic distribution of the flow field in an axial piston pump with a single piston-valve plate’? Please clarify and improve it.
What is the single piston-valve plate in the axial piston pump?
Is it a plate in the pump? And the pump only has one single valve plate.
The introduction does not give enough explanation. And it is difficult to understand the concept, which will cause extra difficulties for the readers who are not familiar with this type of pump.
Line 31 on Page 1.
Should it be named ‘Engine-Driven pump’ ?
A reference is preferred if the authors want to mention the detailed technical parameters such as the rotation speed. Also, A380 and B787 represent two types of airliners. I would use A350 as the alternative example if B787 is made one example, as A380 is much larger than B787.
The introduction can be improved.
From Line 41 o Line 64, quite a few literatures on the turbulence model are mentioned. Some of them are not directly relevant, especially considering the discussions in Section 3.
From Line 65 to Line 85, the CFD software packages, which can be used for the numerical simulation of the turbulence model are introduced. But the software package used in the current manuscript (Fluent) is not mentioned until Section 4.3. It seems the discussions about the software packages can be shortened and even moved to Section 4.3 when the computational model is introduced.
The motivation of the current research can be better clarified. The introduction section can explain more on why the assessment of the flow field in the piston pump is important; what research work has not been performed in previous research (in the literature) and what is new in the current work compared to them (new analysis method? new pump structure?).
Section 2 introduces the flow field in the pump.
The section title seems not very clear. Should it be: Flow field in the pump or the structure of the pump valve?
As the definition of the so-called ‘single piston-valve plate’ is not very well illustrated, I suggest the authors can add a figure to illustrate the pump, including its internal components and its working mechanism, and then point out the flow field in the pump.
Figure 3(a) does show the model of the pump, but it is in Section 4, and its illustration is not adequate. It is worth to extend Section 2 by adding more explanation of the pump, and provide enough definitions. Otherwise, it is difficult to understand Figure 1 and the further sections in the manuscript.
Section 3:
The discussions of the turbulence model seems repeated considering the discussions in the introduction section. Can they be combined?
In Table 1, Does the ‘prototype model’ means the actual model in Eq(3)? It is better to use the same name.
Re number can be provided.
Line 213:
How many meshes are used in the simulation at last?
And what Fluent version is used?
Section 4.4
Where is the inlet boundary condition? Only the outlet is annotated in Figure 4.
Table 2 has the caption: ‘The inlet boundary conditions’, but why is Pump outlet flow is set? If it is the outlet flow, why in Section 4.4.2 the outlet ‘is set as the constant pressure outlet with one standard atmosphere’.
How is Figure 5 obtained? Is the inlet flow velocity calculated by Fluent or by other methods? And also, Figure 5 is not clarified well. What is piston moving speed in Figure 5(a) and what is the pump outlet flow in Figure 5(b). The quality of the figure can be improved. The lines are difficult to be distinguished.
From Figure 6 to 11, what are the Position 1, 2, 3, 4?
The figure captions only mention ‘contour picture’? What do the contour figures represent? Mean velocity?
The quality of these figures can also be improved. It is difficult to see the ‘A, B, C, D’ labels.
More details of the PIV test can be provided.
What camera is used and where is the PIV camera located? The PIV camera will take the image for the post-processing, what is the data acquisition card used for? Is there any additional sensors in the experiment? Where is the measurement plane of the flow in the PIV test? How is the uncertainty of the PIV test evaluated (if performed)?
Figure 6 has the piston moving speed 5.9 m/s and the outlet flow 750ml/min. Should it be compared to Figure 13.
If so, it seems the differences of the vortices are quite significant. But in Line 339, it is said ‘the experimental results are almost identical to the numerical results, including the scale, position and occurrence of the vortices’.
Conclusion section:
Line 356: is it a ‘fluid vibration mechanism’? I think only the flow is investigated, no vibration is analysed.
Some discussions of the pump can be moved in the result section.
Comments for author File: Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors corrected the article according to my instructions. The article can be published in its current form, in my opinion.
Author Response
we really appreciate the valuable suggestions and constructive advice given by the reviewer. The guidance from reviewer contributed a lot to the modification and revise of our paper. Thank you very much!
Reviewer 2 Report
My questions have been answered and the manuscript is better organized with more detailed explanations and discussions.
Just some minor issues before accepting it.
The language has been improved a lot. But there are still some minor issues:
Line 91:
For the axial piston pump, the most complex region of flow field located in port plate pair consist of iston and valve plate, figure 2 shows the port plate pair of axial piston pump.
I will change it to:
For the axial piston pump, the most complex region of flow field is in the port plate pair consisting of the piston and the valve plate. Figure 2 shows the port plate pair of axial piston pump.
Line 94:
This may give rise to the service life and energy delivery efficiency reduction of centrifugal the pump as well as vibration, noise and other issues.
Does it mean?
This may reduce the service life and energy delivery efficiency due to the centrifugal force as well as the vibration and noise in the pump.
Line 181: ‘,’ before Figure 4 should be ‘.’
There are some sentences in the manuscript, which are not complete or should be broken into multiple sentences. Please improve it before the publication.
Figure 3(b):
What positions are the pictures corresponding to? Which position is 1 and which one is 4?
The explanation in the response (Responds 11) is enough and captions should be added in Figure 3(b).
Comments for author File: Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
