Ultrasonic Atomization—From Onset of Protruding Free Surface to Emanating Beads Fountain—Leading to Mist Spreading

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Small typographic issues to be addressed at lines 9 (forma-tions), 277 (sequene), 543 (Figure 2011).

It was not very clear what were the input power densities in the paragraph 3.2. A range of input power densities is mentioned at line 561. It seems that higher values were tested (see line 579). How does it apply for instance to the series of images from Figure 7? Is it constant for the whole series?

You may want to double check the links of the reference list. They do not always match the text (I did find errors in the following Refs: 2, 8, 9, 36, 37, 41, 42, 43, 45) . In one case (line 808) the text of the link is not correct (fludis -> fluids) !

Comments on the Quality of English Language

No particular comment on the English. See above for mention of some minor typographic errors.

Author Response

Outlined response to Reviewer 1:

1) Small typographic issues to be addressed at lines 9 (forma-tions), 277 (sequene), 543 (Figure 2011).

We appreciate your careful checking and in particular, your spotting a missing part—which I believe was unfortunately lost during the publisher’s editorial processing of our original ms submitted. Please re-check the relevant parts (in red with gray highlight), especially the last one—the 1st sentence in the last para of section 3.1.

2) It was not very clear what were the input power densities in the paragraph (section?) 3.2. A range of input power densities is mentioned at line 561. It seems that higher values were tested (see line 579). How does it apply for instance to the series of images from Figure 7? Is it constant for the whole series?

Thank you for your precious comments in clarifying the effects (if any) of the input power density. We believe at this stage—along with our previous study—that the relevant statement given in the said section (2nd para): “The specificity as well as uncertainty … in I₀, on the other hand, should be noted to be rather insignificant or even irrelevant over a typical range examined, as reported by Wang et al. (2022).” should be adequate for describing the relevant role of the input power density.

3) You may want to double check the links of the reference list. They do not always match the text (I did find errors in the following Refs: 2, 8, 9, 36, 37, 41, 42, 43, 45) . In one case (line 808) the text of the link is not correct (fludis -> fluids) !

Again having appreciated your thorough checking of our ms, we double-checked all the links of the reference list and spotted the typing error you pointed out. In regards to the reference listing, please keep in mind that: While it is required to indicate references by number(s) in square brackets in the text, we currently keep the author-year format instead (due to any uncertainty/possibility of some references being added during the review process, which should results in changing the numbers). It is to be noted in this respect that the proper numbering is made in the list, References section, in the order in which they appear in the text. I would appreciate it if you could admit at this stage this inconvenience.

Note: The revised (or modified) parts are indicated in red with gray highlight, while the modifications (changed or added) by the authors are shown in red only. The other colored parts are given in pale blue (just for formatting) or in dark blue (for very minor formatting), just for the sake of authors’ editorial commitment (or even obsession). In addition, all the figures are carefully edited for consistency as well as improved clarity.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The current research in the paper is very interesting. It analyzes the dynamic behavior of liquids after the application of ultrasound excitation in terms of frequency, intensity, and power parameters at a free liquid surface. It also enables control over different forms of liquids, ranging from a mere protruding state to a mist-associated state. However, there are some issues that need to be addressed:

(1) The analysis lacks an explanation of experimental errors and uncertainties. (2) What is the height in millimeters from the surface of the ultrasound transducer to the liquid level? (3) Were there any repeat experiments conducted? If so, please provide the number of test repetitions and include error bars and mean values in Figures 3 and 5. (4) Please add a length scale ruler in Figure 6. (5) It would be beneficial to transform the axes of Figure 8 into dimensionless parameters to enhance the universality of the research findings.

Author Response

Outlined response to Reviewer 2:

The current research in the paper is very interesting. It analyzes the dynamic behavior of liquids after the application of ultrasound excitation in terms of frequency, intensity, and power parameters at a free liquid surface. It also enables control over different forms of liquids, ranging from a mere protruding state to a mist-associated state. However, there are some issues that need to be addressed:

Thank you for your positive comments; we are very encouraged!

1) The analysis lacks an explanation of experimental errors and uncertainties.

The reviewer provides vastly important aspects of any experimental work—reproducibility and reliability. In our present experimental study, while the data provided in Fig. 8 and Table 2 do provide—we believe adequately—these two aspects, the authors must admit that the paper lacks in them, along with explicit explanation, for the rest of the data. Some additional comments are given below (comment 3).

2) What is the height in millimeters from the surface of the ultrasound transducer to the liquid level?

As the reviewer questioned, the relevant information could not be found explicitly. In the text (2nd para in Experimental section), the following addition is made: “… the effective liquid depth (i.e., the vertical distance from the center of the oscillator to the free surface of the liquid) kept 25 mm, or 32.5 mm above the vessel bottom …”.

3) Were there any repeat[ed] experiments conducted? If so, please provide the number of test repetitions and include error bars and mean values in Figures 3 and 5.

As indicated above (comment 1), this paper contains no systematic repetitions of the said data sets. In the text of the present paper, instead, the relevant comments are added for both figures: “Further investigation would be needed to confirm the reliability as well as reproducibility of the present findings regarding the data given in Fig. 3.” and “Rather distinctive trends exhibited above are believed to provide mechanistically useful information; however, as in the case of the data in Fig. 3, this series of data analyses would demand the confirmation in both reliability (reducing uncertainties) and reproducibility (evaluating errors), warranting further investigation.” (Fig. 5).

4) Please add a length scale ruler in Figure 6.

The asked ruler is now provided in the figure, as in the rest of image-containing figures.

5) It would be beneficial to transform the axes of Figure 8 into dimensionless parameters to enhance the universality of the research findings.

As positively suggested by the reviewer, the said universality would be what the present authors wish to have as well; however, the work presented in this paper may not reach that level of “completeness” yet. It would be a future work to be challenged towards desired “compilation”, we hope.

Note: The revised (or modified) parts are indicated in red with gray highlight, while the modifications (changed or added) by the authors are shown in red only. The other colored parts are given in pale blue (just for formatting) or in dark blue (for very minor formatting), just for the sake of authors’ editorial commitment (or even obsession). In addition, all the figures are carefully edited for consistency as well as improved clarity.

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The process of ultrasonic atomization sometimes involves a series of dynamic/topological deformations of free surface. This paper focuses on such dynamic interfacial alterations realized by changing some acousto-related operating conditions, including ultrasound excitation frequency, acoustic strength or input power density, and the presence/absence of a “stabilizing” nozzle. This article has obtained valuable results that are of great significance for the development of ultrasonic atomization theory and is recommended for publication. It should be noted that the text size in Figures 1, 4, 8, and Table 1 is not coordinated and needs to be modified.

Author Response

Outlined response to Reviewer 3:

The process of ultrasonic atomization sometimes involves a series of dynamic/topological deformations of free surface. This paper focuses on such dynamic interfacial alterations realized by changing some acousto-related operating conditions, including ultrasound excitation frequency, acoustic strength or input power density, and the presence/absence of a “stabilizing” nozzle. This article has obtained valuable results that are of great significance for the development of ultrasonic atomization theory and is recommended for publication.

Thank you for your very positive comments; we are extremely encouraged!

0) It should be noted that the text size in Figures 1, 4, 8, and Table 1 is not coordinated and needs to be modified.

As suggested by the reviewer, we made possible—besides the publisher’s final editorial— efforts to “coordinate” the appearance of the text size in the figures and the table. In fact, all the figures are carefully edited for consistency as well as improved clarity.

Note: The revised (or modified) parts are indicated in red with gray highlight, while the modifications (changed or added) by the authors are shown in red only. The other colored parts are given in pale blue (just for formatting) or in dark blue (for very minor formatting), just for the sake of authors’ editorial commitment (or even obsession). In addition, all the figures are carefully edited for consistency as well as improved clarity.

 

Author Response File: Author Response.pdf