Experimental Methods for Evaluating Components of Turbomachinery, for Use in Automotive Fuel Cell Applications

Round 1

Reviewer 1 Report

The overall contents and technical material are acceptable. However, the authors must improve writing, in particular, English. I notice many incomplete sentences in the manuscript.

Author Response

Dear Reviewer,

thank you very much for your review, we did a complete proofreading and corrected errors and incomplete sentences in the manuscript.

With kind regards

Prof. R. Vanhaelst

Reviewer 2 Report

This study describes methods and test beds for components of turbomachinery, the friction test bed (FTB) and hot gas test bench (HGTB), for use in automotive fuel cell applications. The HGTB gives important information about the technical design of a turbine and the system. With these two test beds, Ostfalia University can give essential statements about the overall behaviors of turbomachinery. I suggested accepting the paper after minor revision. Some specific comments are as follows:

1. In general, there are still some occasional grammar errors throughout the manuscript, especially the article a comma is missing in many places; please make a spellchecking.

(1) For reference measurements the Ostfalia uses a turbocharger by BorgWarner of the type BV35, which has a radial fully floating bushing bearing, see Figure 1a.

(2) To get an impression of the rotor shaft dynamics and critical frequencies of the system the measured amplitudes are used to create orbital diagrams.

It seems that you are missing a comma. Consider adding a comma.

2. What is the novelty of this work?
3. All variables should be explained.
4. Some figures in the text are not clear, such as Figure 1(b), Figure 6.
5. The introduction section needs more extensive works to synthesize current research and find any research gap to contribute.

Author Response

Dear Reviewer,

thank you very much for your comments, we performed a complete proofreading and corrected the grammar  and comma errors.

Futhermore we corrected the discription of the figure 1a, 1b and 6. Explained all the variables and added current research and literature results in the introduction section.

With kind regards

Prof. R. Vanhaelst

Reviewer 3 Report

The paper is well written, the subject is fitting the journal, and the methodology is clear and adequate. I'm only suggesting to improve the "Summary" section (I would call it "Conclusions") in order to provide a more general description of the activity, stating the main motivations, summing up the methodology and the main results.

Author Response

Dear Reviewer,

thank you very much for your comments. We changed the "Summary" section to "Conlusions" and improved it we additional information.

With kind regards

Prof. R. Vanhaelst