Effect of Axial and Radial Flow on the Hydrodynamics in a Taylor Reactor
Round 1
Reviewer 1 Report
The article contains new interesting results regarding the impact of combined axial through flow and radial mass flux on Taylor-Couette flow in counter-rotating configuration. The article can be published in Fluids but before publication, the article should be significantly improved.
I will list the points that need to be corrected.
1. The part “Introduction” needs to be reworked: references in the text must be in order; a paragraph regarding references [32]- [43] should be added.
2. A part “Nomenclature” should be added, where, in addition to variables, all abbreviations should be described. The authors should consider whether it is necessary to introduce so many abbreviations. They make text difficult to read.
3. A study of grid convergence and a characterization of the grids used should be added, as well as, perhaps, references to the verification of the numerical method.
3. Fig. 1 should be corrected (it is intersected with the text).
4. Figs. 3, 6, 7, 11 should be enlarged.
5. The text in Figs. 3, 6, 7, 9, 13, 14 should be enlarged.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
This paper presents a numerical study of the axial and radial flow on the hydrodynamics in a Taylor-Couette Flow Reactor. The general organization of the paper and the clarity of the writing and content are of acceptable. Good explanation of the numerical results, clear description of the numerical methods. I recommend this paper for journal publication. The figures and data are solid and efficient support the results. But there are some clarification and revision need before journal publication.
1. What is the new finding in this study comparing with the reviewed literature?
2. The main contribution of this study needs further clarify in the abstract.
4. Did you use any turbulence model? Did you use any wall function? More details are needed.
5. Did you consider the boundary layer mesh, what about the yplus?
Author Response
Please see the file attached.
Author Response File: Author Response.pdf
Reviewer 3 Report
This manuscript presents a numerical investigation on the effects of combined axial through flow and radial mass flux (characterized by dimensionless parameters Re and α, respectively) on Taylor-Couette flow in counter-rotating configuration. Detailed and rigorous analysis has been made for the related flow structures, dynamics and bifurcation behavior depending on parameter space (Re, α) with the aid of indices including modal kinetic energy, radial flow intensity and azimuthal vorticity on the inner cylinder at mid-plane. The author computed several key nonlinear properties for different types of vortices and distinguished different flow structures in topology. The present work extends the conventional research related to Taylor flow and provides theoretical support for optimal design of Taylor-Couette flow reactors. The reviewer would like to recommend for publication after a minor revision. Several comments are listed as below:
(1) Validation for the present numerical method against theoretical solutions or previous experiments is suggested to make sure the validity of the simulations.
(2) The word “reactor” in the title looks redundant because the research content in this work is not directly related to any reactor. Instead, it provides more general results that might be applicable for wider applications such as those exemplified in the introduction.
(3) Why does the viscosity-related coefficient usually in a form like (1/Re) disappear from the last term in the (left) momentum equation of Eq. 1?
(4) Does the abbreviation TVF indicate Taylor vortex flow? It would be better to indicate this point where the latter first appears, e.g., in the introduction.
(5) The meaning of variable Ω (omega) in Eq. 2a was not found in the text. Angular speed? If so, please unify the notation in the context.
(6) Why was the coefficient of the integration in Eq. 12 set as 1/π, not 1/2π? As we can see that the integral is performed in a range of θ = 0–2π.
(7) Why did the author limit the ranges within Re = -20–20 and α = -20–20? To avoid turbulence transitions or to meet the operating condition of reactors?
(8) Line 2 in the caption of Fig. 2: model -> modal.
(9) Line 154: leving -> leaving.
(10) Line 3 in the caption of Fig. 4: correspond -> corresponds.
(11) Line 209: strengthen -> strengthens for?
(12) Line 215: sufficient -> sufficiently.
(13) Line 219: Qualitative -> Qualitatively.
(14) Line 238: propagate -> propagates.
(15) Line 273: cancel the “=” sign?
(16) Line 300: an -> a.
(17) Line 81: Reo = -25 -> Reo = -75? In P.3, the author claimed that the inner and outer Reynolds numbers are fixed to Rei = 100 and Reo = -75, respectively.
Comments for author File: 
Comments.docx
Author Response
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Author Response File: Author Response.pdf
Reviewer 4 Report
This reviewer recommends publishing this paper in its current format after minor corrections. However, the idea is pristine and could add more to the community. Also, the results are interesting. The problem is well defined and explained.
Note: The paper is well written and reads well.
Very interesting figures.
Minor concern: All legends for figures should be enlarged enouth to be clear.
Figure 9, for alpha=4 the results is doublicated in the figure and should be located as markers rather than dotted and dashed lines.
Author Response
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Author Response File: Author Response.pdf
