Flow Analysis of PM/NO_X Aftertreatment System for Emergency Generator

Round 1

Reviewer 1 Report

Remark:

1. It would be desirable to present a mathematical formulation of the CFD problem, which includes the appropriate systems of differential equations of continuous mechanics (RANS, taking into account the reactant medium, porous medium and DPM) with the appropriate initial and boundary conditions. This would allow a deeper understanding of the problem to be solved and make it easier for other researchers to make similar calculations if necessary.
2. In paragraph (2.2. Analysis conditions) for some reason does not specify the energy equation and Species Transport Equations, given that the article describes the use of catalysts, for example, to convert NOX to H2O and N2, ie there are reactants and so on. It is also unclear whether radiative heat transfer was taken into account, as the exhaust gas temperature is quite high.
3. It is not entirely clear why the RNG k-ε Model turbulence model was chosen in the article, and not the Realizable k-ε Model, or other RANS models.
4. In equations (1) - (5), (7) do not decipher all the physical quantities included in them and do not specify their dimensions.
5. The article uses non-system units of measurement, such as inches.
6. From the text of the article it is not known whether the study of mesh convergence was performed for the presented results of numerical simulation. The parameters of the calculation grids (mesh) are not given. There are also no comparisons of the obtained results of numerical simulation with the data of other researchers, which does not allow to assess the reliability of the presented data.
7. Figures 5, 7, 11, 13 show qualitative legends, or none at all, which does not allow to evaluate quantitative results. In addition, Figures 5, 7, 13 show "NH3 Distribution…", but do not indicate the concentration of the distribution: mass, volume, molar or the corresponding fractions.
8. The caption to Figure 6 indicates the back pressure, but not on the graph.
9. In Figures 8, 10 the inscriptions on the y-axis are shown in the opposite direction.
10. The article does not contain data on the influence of the studied parameters on the thermal state of the equipment of emergency diesel generators.
11. In the conclusions there are almost no quantitative estimates of the results.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

1- The abstract needs to be revised. The most important findings of the article should be included in it.

2- The references examined in the introduction section are very few. In order for the reader to have a deeper understanding of the current state of research in this field, it is necessary to have at least 15 references.

3- The information provided in the field of numerical simulation is not complete and the authors need to provide complete information in the article, including the type of solution used, information of the element used, etc. in the article.

4- Authors should present the most important innovation of the article in the article. At the moment I do not see any innovation in the article. The differences between the research done in this article and other articles should also be mentioned.

5- How authors are confident in the accuracy of their simulation results. How and by what means they have confirmed their numerical results. This issue should be clearly stated in the article.

6- In Figure 5, the authors should present the differences in the results for the circular type and the rectangular type with a reason.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

The manuscript is interesting but written clumsily. It can be considered after major revision. Some hints for authors.

1. Please review recent CFD achievements on the topic of similar gas flow analysis, and gaseous pretreatment according to the part of reactors/engines. Write there also advantages of CFD over other methods.
2. urea injector both should be in 145 and 146 in small letters similar like discrete at 146 Solid and discrete phase model at 150 lines. Please check all manuscript
3. Please compare your results with other works both experimental and theoretical. Put in the table this comparison. For example; https://doi.org/10.3390/catal10121423, https://www.cheric.org/research/tech/periodicals/doi.php?art_seq=1753140

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

The authors correspond to my question. Now it can be published