Capturing the Motion of the Free Surface of a Fluid Stored within a Floating Structure
, Jeffrey Steynor 1, David I. M. Forehand 1, Thomas Davey 1, Tom Bruce 1 and David M. Ingram 1Round 1
Reviewer 1 Report
The paper describes some experimental techniques to track the free surface of a fluid in presence of strong oscillations due, e.g., to sloshing. Optical tracking is suggested as a strong method with limited uncertainty.
The topic is of interest and the proposed technique could be of applicative interest. However, there are some flaws that require a revision.
Major comments
In the introduction, a list of different techniques are introduced, explaining some advantages and disadvantages. Most of these techniques belong to coastal engineering, where often it is requested the free surface measurement of breaking waves and, in general, of water surface with strong inclination. However, ultrasound techniques are cited en-passing, without a proper description. Ultrasounds have been used with the sensor above the free surface, with propagation in air, but also with the sensor below the free surface, with propagation in water. See, e.g., DOI: 10.1007/BF00191017, DOI: 10.1007/s00348-010-0881-5 and references therein.
As for the delay in the response of the conductive types with small spacing, see also the technique in DOI: 10.1016/S0378-3839(00)00068-5, with two wires parallel to the beach and detached, in order to avoid the water film interference.
As for the metallic wires, it should be mentioned cross-talking between probes, if more than one probe is immersed, and the impossibility to use resistive circuits if the walls of the tank are metallic and without electrical insulating coating.
Minor comments
The units of measurements must be in normal font
Author Response
We include the response to both reviewers in one document. Thank you for the valuable feedback.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This manuscript discusses an experimental design of measuring the motion of the free surface of a fluid stored within a floating structure. I think the results are solid and clearly conveyed so I recommend a publication of the manuscript. Following are a few places that I think can be further improved.
1, figure 2(a), the axis x should be x'. the bottom distance measurement 0.17 is slightly displaced.
2, This is minor, but it would be better to align fig. (a) and (b) vertically like in a mechanical drawing, but since (a) is not a top view, I am not sure what exactly to do.
3, in section 3.3, I think experiment setup and roll and yaw angles are less clear, I am not sure why roll and yaw angles (in fig. 6) are not around 0. I also suggest to use the colored lines to distinguish the different angels.
4, in fig. 8, it would be better to use colors to distinguish each trajectory or highlight a few. Also I think a 3D reconstruction of the markers' trajectories (overlaid with a schematic of the velocity of flow and interface in the tank) is needed. After all, it is a key result of this paper.
Author Response
We include the response to both reviewers in one document. Thank you for the valuable feedback.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
I have now read the revised version of the manuscript. The Authors have fulfilled the requests, the manuscript can be accepted.
