Dynamic Analysis of Wake Characteristics of the Circular Cylinder with a Dimpled Surface
Round 1
Reviewer 1 Report
PIV and POD methods are used to analyze the wake flow of the circular cylinder with different dimpled surface. Here are some suggestions:
1. Some recent similar work should be introduced.
2. More comparisons among different surface forms and related conclusions is suggested.
Author Response
Reply to referee 1
We are very grateful for this review’s detailed comments that have helped us improve significantly this manuscript. The major changes to the manuscript have been highlighted in red. Following are actions we have taken to address specific issues raised by the reviewer.
Reviewer’s comments:
- Some recent similar work should be introduced.
Author’s response:
Some recent similar work has been added.
Reviewer’s comments:
- More comparisons among different surface forms and related conclusions is suggested.
Author’s response:
Related discussion content has been added to the paper.
Reviewer 2 Report
This paper studies the wake characteristics of the circular cylinder with a dimpled surface. PIV tests are presented to obtain the wake fields, which are then processed by the POD technique. The topic is interesting, the experiments are well designed, and the paper is well written. However, some major shortcomings should be improved or explained before it can be recommend for publication.
1. Most importantly, the study of a dimpled surface is inspired by its function for drag reduction, as discussed in Line 56-61. However, no discissions are provided concerning the connection between the observed wake characteristics and the reason for drag reduction.
2. Fig. 6, it is suggested to provide A, B, and C in the figure.
3. It is not clear how the authors obtain the data in Fig. 8.
4. A figure of the circular cylinder in the circulating tank during the experiments is suggested.
5. It is suggested to provide some comparisons between the present experimental data and previous experimental data at similar conditions. Some comparions for the results of the smooth circular cylinder would be useful to validate the present experiments.
6. The literature review should be largely enriched, e.g., in terms of drag reduction measures and wake characteristics measurements. Some suggested references include
Investigation of a drag reduction on a circular cylinder in rotary oscillation
Low drag solutions for suppressing vortex-induced vibration of circular cylinders
Torsional vibration of a circular cylinder with an attached splitter plate in laminar flow
Experimental study on aerodynamic characteristics of a large-diameter ice-accreted cylinder without icicles
Passive control of VIV with drag reduction
Author Response
Reply to referee 2
We are very grateful for this review’s detailed comments that have helped us improve significantly this manuscript. The major changes to the manuscript have been highlighted in green. Following are actions we have taken to address specific issues raised by the reviewer.
Reviewer’s comments:
- Most importantly, the study of a dimpled surface is inspired by its function for drag reduction, as discussed in Line 56-61. However, no discissions are provided concerning the connection between the observed wake characteristics and the reason for drag reduction.
Author’s response:
Related discussion content has been added to the paper.
Reviewer’s comments:
- Fig. 6, it is suggested to provide A, B, and C in the figure.
Author’s response:
Revised.
Reviewer’s comments:
- It is not clear how the authors obtain the data in Fig. 8.
Author’s response:
Fig. 8 provides the vortex features and the related parameters, in which LR, a, b and other parameters have been defined in section 4.2 of this paper. The data of LR, a, b in Fig. 9 are calculated from the coordinates between the points.
Reviewer’s comments:
- A figure of the circular cylinder in the circulating tank during the experiments is suggested. Author’s response:
Revised.
Reviewer’s comments:
- It is suggested to provide some comparisons between the present experimental data and previous experimental data at similar conditions. Some comparions for the results of the smooth circular cylinder would be useful to validate the present experiments.
Author’s response:
Related discussion content has been added to the paper.
The experiment was carried out in a circulating tank whose length is about 4 m long with a rectangular cross-section of 0.3 m × 0.45 m (width × height), the circulating water tank system is mainly composed of water pump, rectifier, steady flow section, experimental section, flow meter and PLC control cabinet. PIV system is mainly composed of light source, high-speed camera, tracer particles, and image processing system.
Reviewer’s comments:
- The literature review should be largely enriched, e.g., in terms of drag reduction measures and wake characteristics measurements. Some suggested references include:
Investigation of a drag reduction on a circular cylinder in rotary oscillation;
Low drag solutions for suppressing vortex-induced vibration of circular cylinders;
Torsional vibration of a circular cylinder with an attached splitter plate in laminar flow;
Experimental study on aerodynamic characteristics of a large-diameter ice-accreted cylinder without icicles;
Passive control of VIV with drag reduction.
Author’s response:
The literature review has been extensively enriched in this paper.
Round 2
Reviewer 2 Report
All comments are addressed properly. I recommend the publication in the present form.
