Flow Characteristics of a Dual Sweeping Jet Impinging on a Flat Surface

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this study, the authors investigated numerically the flow characteristics of a dual sweeping jet impinging on a flat surface. In general, the manuscript is clear and the results are correctly discussed. Meanwhile, I note some shortcomings that the authors should address. Thus, I recommend a major revision.

Please find below my comments:

• The originality of the study is not clear. What is the "utility" of this study? What is the contribution of this study in the current state-of-the-art of this research area?
• Following the first comment, the last paragraph of the introduction section has to be rewritten.
• The obtained results have to be compared with the findings already existing in the literature. This allows to better highlight the contribution of the authors. 
• Did the authors validate their results? If yes, please explain how? If not, please explain why?
• Please cite some recent works in the area of fluidic oscillator:

1/ Joulaei, A., Nili-Ahmadabadi, M., & Ha, M. Y. (2023). Numerical study of the effect of geometric scaling of a fluidic oscillator on the heat transfer and frequency of impinging sweeping jet. Applied Thermal Engineering, 221, 119848.

2/ Tu, T., Chen, S., Shi, Y., & Li, W. (2023). Flow mechanism and heat transfer characteristic of sweeping jet impinging on confined concave surfaces. Physics of Fluids, 35(1).

3/ Song, J., Wang, S., Qiu, Z., Peng, D., Liu, Y., & Wen, X. (2024). Flow mechanism study and geometrical parameters analysis of fluidic oscillators based on pressure-sensitive paint measurements and modal analysis. Experiments in Fluids, 65(3), 38.

4/ Lai, B., Li, H., Wang, S., Xu, Z. Q. J., Song, J., Liu, Y., & Wen, X. (2025). Analysis of high subsonic sweeping jet external flow characteristics and velocity using schlieren visualization and schlieren image velocimetry method. Experimental Thermal and Fluid Science, 163, 111397.

5/ Lakehal, A., Aksouh, M. & Medelfef, A. (2025) Numerical Study of the Compressible Air Flow Through a Two-output Fluidic Oscillator. Journal of Applied Fluid Mechanics, 18(4), 880-891.

6/ Hussain, L., & Khan, M. M. (2022). Recent progress in flow control and heat transfer enhancement of impinging sweeping jets using double feedback fluidic oscillators: A review. Journal of Heat Transfer, 144(12), 120802.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The paper presents the results of research on the dynamics of water flow in a fluidic oscillator generating the dual sweeping jet. The analyzis of the flow dynamics was carried out on numerical calculations at three different values of Reynolds numbers using the kw-SST model. It was found that at higher Reynolds numbers, the DSJ synchronisation can be improved by using lower aspect ratio (AR = 1.5 or 1.0). In my opinion, the paper has an element of scientific novelty and may be interesting to people involved in fluid mechanics. However, their authors indicated in the conclusions that improving the shape of the fluidic oscillator requires further research. Nevertheless, I believe that it is worth considering publishing the paper in Actuators. Before publishing the results, I suggest that the authors clarify two issues.

1. Line 262: “…the roughness effects of a fluidic oscillator during experiment with dense medium like water.” What does dense medium mean?
2. Lines 404-405 and others (for example 461-463; 468-469; 531-532 and other text fragments): “It was also observed that the strength of extra-loop is always smaller than the primary loop which helped formation its – right-loop of shared FBC formed extra-loop in left FBC of LPN.” Explain the meaning of the words "the strength", "less strength”..

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This article investigates the flow dynamics of a dual sweeping jet (DSJ) impinging on a flat surface. It focuses on the synchronization of sweeping jets at different Reynolds numbers and aspect ratios. The topic is relevant to fluid dynamics and engineering applications involving fluidic oscillators.

The study addresses an interesting problem with potential practical applications. The numerical approach using the  SST model is appropriate for capturing flow dynamics. The investigation covers a broad range of cases. However, the introduction lacks a concise presentation of the research gap and objectives. Some references are outdated, and recent developments are underrepresented. This has to be revised before accepting the paper. Moreover, the conclusions are somewhat general and do not critically discuss the limitations of the study or suggest specific future research directions.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors responded to all my comments. The paper can be accepted. 

Reviewer 3 Report

Comments and Suggestions for Authors

The improvements, particularly in the introduction, references, and conclusion, have strengthened the clarity and scientific rigor of the study. The refined presentation of the research gap and objectives, along with the inclusion of recent literature, provides a more comprehensive context for the work. Additionally, the revised conclusions offer a more critical discussion of the study’s limitations and future research directions.

Based on these improvements, I find the manuscript significantly enhanced and suitable for publication in Actuators.