Toward the Utilization of 3D Blading in the Cantilevered Stator from Highly Loaded Compressors

Round 1

Reviewer 1 Report

The revised manuscript needs to incorporate the following suggestions raised by the reviewer:

1. The grid independence test details are missing. Which parameter was taken into account in the grid independence test? What was the percentage change in that parameter's value in relation to the grid size? The authors must elaborate on this in the annexure section.

2. Can the authors specify what the value of Y+ was, even though they stated it was less than 5?

3.Please add a space between a numeric value and a unit. Say, for example, 288.15 K (line 120).

4. How much was the deviation in the value obtained from CFD and the experiment?

5. Authors must either compare the results of the CFD code to available literature for a similar case or to an experiment. This is an important parameter for benchmarking the CFD code.

 

6. What could be the cause of the deviation in the trend of the radial distribution of aerodynamic performances for case A1B2 at φ =0.46 compared to others?

Author Response

Question:

• The grid independence test details are missing. Which parameter was taken into account in the grid independence test? What was the percentage change in that parameter's value in relation to the grid size? The authors must elaborate on this in the annexure section.

Reply:

• Thanks for your professional comments. The grid independence test has been processed in Ref. [31,32] with the same facilit In Ref. [31,32], the grid with different node numbers were tested, and the key parameters such as the loss, the static pressure rise coefficient, and the flow angle would not change more than 0.1% compare between the selected mesh and the 1.5 times finer mesh. The description has been written in line 115 in the revised manuscript.

 

Question:

• Can the authors specify what the value of Y+ was, even though they stated it was less than 5?

Reply:

• Thanks for your professional comments. Y+ is about 2.5 in the region close to the transition position near the leading edge, and Y+ is about 0.5 near the trailing edge. The description has been written in line 112 in the revised manuscript.

 

Question:

• Please add a space between a numeric value and a unit. Say, for example, 288.15 K (line 120).

Reply:

• Thanks for your professional comments. The units have been checked carefully and corrected in the revised manuscript.

 

Question:

• How much was the deviation in the value obtained from CFD and the experiment?

Reply:

• Thanks for your professional comments. The difference between the experiment result and the CFD result has been plotted in Figure 31. Figure 31 indicates the CFD results have high reference value, so the above numerical analysis results are credible.

 

Question:

• Authors must either compare the results of the CFD code to available literature for a similar case or to an experiment. This is an important parameter for benchmarking the CFD code.

Reply:

• Thanks for your professional comments. The compare between the CFD result and the experiment result has been processed in Ref [30] in detail, which shows the CFD setting-up used in this paper have the best matching degree to experimental results.

 

Question:

• What could be the cause of the deviation in the trend of the radial distribution of aerodynamic performances for case A1B2 at φ =0.46 compared to others?

Reply:

• Thanks for your professional comments. With blade sweep in the hub region, the blade loading in the midspan would increase. However, there is a critical value for the sweep height, while it is too small to fully decrease the separation zone and is big enough to make the midspan separation, to make the flow worsen at the near stall condition.

Author Response File: Author Response.docx

Reviewer 2 Report

Review Report (applsci-2266862)

Toward the Utilization of 3D Blading in the Cantilevered Stator 2 from Highly Loaded Compressors

The article is concerned with the 3D blading in the cantilevered stator. The authors numerically investigated the effect of the sweep, dihedral, and compound sweep & dihedral, respectively, through which the flow mechanisms are revealed and recommendations of the different parameters are provided. The theory is validated by an experiment, which consists of redesigning a cantilevered stator, and a detailed comparison of the flow field with the datum scheme is shown. The presented work looks interesting and new in literature.

 

I suggest that the authors must  take into account the following corrections/suggestions:

 

1.     The article is well-written, but there are some grammatical and typo errors; the paper should be free from all types of errors.

2.     Polish the abstract precisely by presenting some significant and key outcomes.

3.     The introduction section should have some most recent and new publications.

4.     What are the effects of 3D blading on the cantilevered stator? Give more detail.

5.     Recheck figures 34-36. There looks like something is wrong.

6.     Can you provide some future extensions for the presented work?

 

Concluding Remark:

From my point of view, the results presented are new and interesting. Hence, I recommend the paper for publication. However, the above comments or suggestions must be incorporated before publication.

Author Response

Question:

• The article is well-written, but there are some grammatical and typo errors; the paper should be free from all types of errors.

Reply:

• Thanks for your scrupulous comments. The grammatical errors have been checked carefully and corrected in the revised manuscript.

 

Question:

• Polish the abstract precisely by presenting some significant and key outcomes.

Reply:

• Thanks for your professional comments. We have added the quantitative values obtained in the paper to the abstract

 

Question:

• The introduction section should have some most recent and new publications.

Reply:

• Thanks for your professional comments. After re-searching the references and research status, we added the recent studies on the three-dimensional cantilever static in the introduction.

 

Question:

• What are the effects of 3D blading on the cantilevered stator? Give more detail.

Reply:

• Thanks for your professional comments. The effects of 3D blading on the cantilevered stator has been discussed in Section 3. To make conclusion clear, the conclusive sentences have been added in the end of every section.

 

Question:

• Recheck figures 34-36. There looks like something is wrong.

Reply:

• Thanks for your scrupulous comments. Figures 34-36 are screenshots in the previous manuscript by mistake, and they had been corrected with high resolution pictures in the revision.

 

Question:

• Can you provide some future extensions for the presented work?

Reply:

The future extension to our presented work is to investigate the effect of hub clearance on the selection of 3D blading parameters. In the present work, the clearance is fixed. However, the effects of 3D blading should be different while the leakage flow has the different strength, and the leakage flow strength is affected by the hub clearance. Hence, the clearance size on the 3D blading cantilevered stator will be investigated in the next step.

Author Response File: Author Response.docx