Experimental Evaluation of Axial Reaction Turbine Stage Bucket Lossesâ€
Round 1
Reviewer 1 Report
The paper documented the measurements in the turbine wake behind the nozzle and bucket using two five-hold probes. The biggest issue with this 'paper' is that this doesn't read like a paper but more like a lab report. In the introduction section, no background was given. What is the motivation of this research? Why would this research be important? The introduction section of the current paper can be merged into the second section without any problems.
There are also problems with the details of the experimental setup. Is the five-hole probe made in house? I assume this because I don't see a model number. Then what is the dimension of this device? It took me a while to figure that you had two rotation stages to rotate the probe in the calibration. The angle notations in the picture looks very confusing.
The main take away from the uncertainty analysis is that the angle is very important which contribute a lot to the results. Then I would think the authors want to emphasize the importance of using a five-hole probe to make the measurement. This rises the question, how to improve the uncertainty? Is a five-hole probe better than a four-hole probe? Or are there any other ways to improve it? There are many other points to dig into.
As I said in the beginning, this 'paper' is more like a lab report. Therefore, I don't recommend publication.
Author Response
The reviewer stated in his review that he does not recommend the submitted article for publication. The reviewer's comments will be summarized in turn within this cover letter, with subsequent explanation by the authors.
- The biggest issue with this "paper" is that this doesn´t read like a paper but more like a lab report. In the introduction section, no background was given. What is
the motivation of this research? Why would this research be important?
The introduction of the paper was really very brief, so it has been edited/completed. Since this is a presentation of experimentally obtained data, it is natural that the paper may appear to be a lab report. Any similarly focused paper must include a basic description of the measurement loop as well as a brief summary of the measurement methodology.
- Is the five-hole probe made in house? Then what is the dimension of this device? It took me a while to figure that you had two rotation stages to rotate the probe in the calibration. The angle notations in the picture looks very confusing.
No, the probes were not manufactured in house. The serial number was added within the paragraph 3.1 (Probe calibration)
We do not know what the reviewer means specifically by "dimension of this device". The dimension of the measuring or calibration loop, or of the probes themselves...?
The problem of probe calibration is discussed in the already mentioned chapter 3.1 (Probe calibration), in which a 3D sketch of the probe is shown with the orientation of the angles (see Fig. 3). Unfortunately, we do not have a more illustrative picture that would demonstrate these angles even more clearly.
- How to improve the measurement uncertainty? Is a five-hole probe better than a four-hole probe? Or are there any other ways to improve it?
A paragraph on the precise alignment of the probes using a special protractor and air discharge tunnel was added to the article. Unfortunately, we cannot comment on the question whether a 4-hole probe is "better" than a 5-hole probe, because the measurements were realized only with 5-hole probes. Of course, there are various other measurement methods, but this article does not aim to compare different measurement techniques.
Analysis of measurement uncertainties is an integral part of any experimental research. The results of these analyses are intended to make it clear what measurement errors have been made. This was certainly not intended to emphasize the importance of using a
5-hole probe, as mentioned by the reviewer.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The paper presents and interesting study on a high reaction single stage turbine, in which the losses are analyzed and avaluated, in the secanario of four modes of operation.
The mathematical theory look good, also the model seems correct. The paper is an extension of a conference paper, which i could not find / read. AS an extension i would've expected more references and descriptions of the same topic literature in the introduction part, as right now there are only few. This part might be extended.
Other that than the paper look good and is correct.
Author Response
The reviewer recommends the submitted article for publication. The reviewer only recommends extending the introduction and adding more references to the literature. These modifications have been incorporated into the current version of the paper.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Significantly improved.
