Characteristics of Plane Gate Vibration and Holding Force in Closing Process by Experiments

Round 1

Reviewer 1 Report

The paper is focused on plane gate vibration. The analysis is based on model measurement, where gate vibrations in three directions and gate holding force were recorded.

I think the paper is well written and I do not have any objections or additional comments.

Author Response

Thank for your comments.

Author Response File: Author Response.docx

Reviewer 2 Report

Overall, I think it's a very well-written paper. However, there are some big and small demerits. If some improvements are supplemented, the paper can be published as a very good paper. Please refer to the following comments.

• It would be better if the theoretical background comes before the part describing the experimental design and results. The theoretical background and the experimental results are not distinguished in the submitted version. In other words, if you differentiate between what you knew before the experiment and what you learned from the experiment, the readers will be able to better understand the paper.
• Figure 3 may not be an effective figure to express results. Consider ways to visualize differences between results more effectively. For example, consider alternatives such as opening on transverse axis, Frequency on longitudinal axis, and drawing interpolated color contours (Note, these are the main methods used to express wavelet analysis results).

• Figure 5b and Figure 8b have a similar problem. In these figures, it is difficult to distinguish between symbols. I think it would be better to use a more effective method to show the results.

• Quantified values for the results should be presented in the ‘Conclusion’ and ‘Abstract’ section. These may increase the reliability of the paper.

• I recommend changing the title of the paper so that the reader can know that the paper was written through an experiment. I think the strength of the paper is the experiment. In order to, I believe the authors need to emphasize the point.

Author Response

Point 1:

It would be better if the theoretical background comes before the part describing the experimental design and results. The theoretical background and the experimental results are not distinguished in the submitted version. In other words, if you differentiate between what you knew before the experiment and what you learned from the experiment, the readers will be able to better understand the paper.

Response 1:

In the previous research results, the vibration of plane gate is mostly obtained under the condition of fixed opening, but there are few studies on the continuous process of closing the gate. At the same time, the few existing research cannot fully reflect the vibration characteristics of the gate in closing process. So, there is no clear distinction between what we knew before the experiment and what we learned from the experiment in this paper. Only in Section 3.1 (corresponding line 129 ~ 132) and Section 3.2 (corresponding line 234 ~ 237), the theoretical aspects are described.

 

Point 2:

Figure 3 may not be an effective figure to express results. Consider ways to visualize differences between results more effectively. For example, consider alternatives such as opening on transverse axis, Frequency on longitudinal axis, and drawing interpolated colour contours (Note, these are the main methods used to express wavelet analysis results).

Response 2:

According to the Reviewer’s comments, the label of the coordinate axis in Figure 3 indicating the gate opening has been modified, as shown in the figure below. The corresponding context (“In coordinate axes, the opening index 1~5 represent the gate opening ratio e = 0.8, 0.5, 0.3, 0.2 and 0.1, successively”) at line 140 has been deleted. Figure 3 shows the relationship between frequency and amplitude of vibration acceleration at different gate opening heights. Although the wave lines are a little messy, the relationship between the gate vibration acceleration and frequency can be clearly identified, especially for peers. So the power spectral density is not used here.

 

Point 3:

Figure 5b and Figure 8b have a similar problem. In these figures, it is difficult to distinguish between symbols. I think it would be better to use a more effective method to show the results.

Response 3: 

Based on the Reviewer’s comments, in order to distinguish the results at different upstream water levels, we have modified the figure 5b and figure 8b as follows. The modified figure 5b and figure 8b are listed in the Word version

 

Point 4:

Quantified values for the results should be presented in the ‘Conclusion’ and ‘Abstract’ section. These may increase the reliability of the paper.

Response 4: 

On the basis of Reviewer’s comments, the dominant frequency of self-excited vibration of the plane gate in closing process (line 17) and the correlation results between vibration and holding force (line 23~24) are added in the abstract. A small modification is made to change ‘ten’ to ‘10’ (line 432) in the conclusion, which is more significant.

Line 17, “Gate vertical vibration is self-excited vibration with a frequency of 7~14 Hz” was added.

Line 23~24, “In the crawl stage the average of correlation coefficient in lateral, vertical and horizontal direction is -0.723, 0.733 and -0.664, respectively.” was added.

Line 432, we change the ‘ten’ into ‘10’ in the conclusion.

Point 5:

I recommend changing the title of the paper so that the reader can know that the paper was written through an experiment. I think the strength of the paper is the experiment. In order to, I believe the authors need to emphasize the point.

Response 5: 

We accept to the Reviewer’s comments and make some modifications to the title of the paper. Revision of the subject of the article: “Characteristics of Plane Gate vibrate and Holding Force in Closing Process by Experiments”. (line 2)

Author Response File: Author Response.docx

Reviewer 3 Report

Very important comments (critical ones):

• Some discussion about repeatability is necessary. You may, for instance, repeat 5 times an experiment and plot gate position vs. time to discuss its repeatability. Or the vibration spectrums.
• The document describes a physical model (scale 1:25) but the tests descriptions make me think that they were carried on full scale prototype (difficult to belive). If the tests are carried on the prototype the physical model is irrelevant. If the tests are carried on the physical model, what is reported in the document, experimental results or extrapolated results from model to prototype? If the tests are carried on the physical model, the reported height should be the physical model height.

• Please state what means “standard deviation” for you, or better use different words. For an English reader it is a statistics term.

Important comments:

• Time arrow problems. The document states at 3.1.1 paragraph 2: ” As gate opening decreases…”. This is confusing; at 3.1.1 the fixed gate opening is discussed, the gate opening increased…

        It is very easy to change the description to avoid confusion.

• See Fig 3 Spectrums. The graphs should be self-explained. Please, replace index numbers by its opening ratio. Or, write the index equivalence on Figure description. 
• Figure 1. It is hard to believe that the physical model uses a servo motor. It is very hard to believe that the prototype uses a servo motor. The servo motors definition according Wikipedia: “A servomotor is a rotary actuator or linear actuator that allows for precise control of angular or linear position, velocity and acceleration.” Servo motors allow using active dampening to reduce vibrations…

Language comments:

• 2 Equation (4) terms should be more exacts:

         Ws is water column weight…

          Px-Pi is vertical hydrodynamic force

• 2.2 last paragraph: missing if

         Only if the hydrodynamic…

Author Response

Very important comments (critical ones)：

Point 1:

Some discussion about repeatability is necessary. You may, for instance, repeat 5 times an experiment and plot gate position vs. time to discuss its repeatability. Or the vibration spectrums.

Response 1:

It is really true as Reviewer suggest that model test should be repeated. In fact, each group experiment was tested three times in our physical model test. During the experiment, the observer always paid more attention to the variation of signal waveform on the acquisition instrument. Once there is a strange waveform, we would stop the data collected and find out the cause. Then re-start the experiment again.

 

Point 2:

The document describes a physical model (scale 1:25) but the tests descriptions make me think that they were carried on full scale prototype (difficult to believe). If the tests are carried on the prototype the physical model is irrelevant. If the tests are carried on the physical model, what is reported in the document, experimental results or extrapolated results from model to prototype? If the tests are carried on the physical model, the reported height should be the physical model height.

Response 2:

We studied the characteristics of the plane gate vibration in closing process through the physical model test. In order to make the peers intuitively understand our results from the view of practical engineering, the model results were converted into prototype results through the model similarity law. In manuscript, the height we’re talking about is the height of the prototype.

Line 103~104 in manuscript, we explained the problem of water depth “The upstream water depth were 0.64 m, 0.72 m, 0.8 m and 0.92 m in the physical model test, successively (corresponding prototype depth is 16 m and 18 m, 20 m and 23 m, respectively)”.

 

Point 3:

Please state what means “standard deviation” for you, or better use different words. For an English reader it is a statistics term.

Response 3:  

Standard deviation is a statistic term, and we use such a parameter to reflect the deviation degree of the variation of the holding force under the condition of the fixed gate opening. By studying the standard deviation of holding force, we can obtain the characteristics of the pulsation pressure at different gate opening to a certain degree.

 

Important comments：

Point 4:

Time arrow problems. The document states at 3.1.1 paragraph 2: ” As gate opening decreases…”. This is confusing; at 3.1.1 the fixed gate opening is discussed, the gate opening increased…

Response 4:  

We have made correction in the manuscript according to the Reviewer’s comments.

Line 140, the statements of “the acceleration in three directions increases gradually with the gate opening increase” were corrected as “the acceleration in three directions decreases gradually with the gate opening decrease”.

Line 142, the statements of “flow pulsation pressure increased with gate opening increase” were corrected as “pointed out that flow pulsation pressure decreased with gate opening decrease ”, which ensures context consistency.

 

Point 5:

See Fig 3 Spectrums. The graphs should be self-explained. Please, replace index numbers by its opening ratio. Or, write the index equivalence on Figure description.

Response 5:  

Considering the Reviewer’s suggestion, the improper label of coordinate axes in Figure 3 has been modified in the manuscript, as shown in the figure below. X-axis is expressed by the gate opening ratio e. The modified figure 3 is listed in the Word version.

 

Point 6:

Figure 1. It is hard to believe that the physical model uses a servo motor. It is very hard to believe that the prototype uses a servo motor. The servo motors definition according Wikipedia: “A servomotor is a rotary actuator or linear actuator that allows for precise control of angular or linear position, velocity and acceleration.” Servo motors allow using active dampening to reduce vibrations…

Response 6:  

This manuscript describes a physical model test. The servo motor not only can meet the operating conditions converted from the prototype by similarity law, but also change the operating speed of the model gate so as to study the vibration characteristics of the plane gate under different operating speeds.

 

Language  comments：

 

Point 7:

3. 2 Equation (4) terms should be more exacts:

         Ws is water column weight…

          Px-Pi is vertical hydrodynamic force

3.2.2 last paragraph: missing if

         Only if the hydrodynamic

Response 7:  

We are very sorry for our incorrect writing in section 3.2. The language error has been correspondingly revised in the paper.

Line 235, “weight” was added.

Line 236, the statements of “vertical hydrodynamic pressure” were corrected as “vertical hydrodynamic force”.

Line 307, “if” was added.

Author Response File: Author Response.docx