Structural Optimization of Slotting Nozzle Used to Improve Coal-Seam Permeability
Round 1
Reviewer 1 Report
Paper is more academic than practical. Some improvement is necessary.
Things that should be revised are as follows.
Line 110 “2.2 O rthogonal optimizati on of slotting nozzle structural parameters” – title not adequate to the content. Figure 3. – there is no units and difficult to read scale. Authors mention uniaxial compressive strength but there is luck of discussion how it influences results.Author Response
Reviewer 1:
Line 110 “2.2 Orthogonal optimization of” – title not adequate to the content.
Response: According to Section 2.2, we modified the title. “Design of slotting nozzle structural parameters orthogonal optimization.”
Figure 3. – there is no units and difficult to read scale.
Response: The figure 3(a) unit is m/s, and figure 3(a) unit is MPa. We have modified the Figure 3 to show the model scale, (a) and (b) have the same model scale.
Figure 3. (a) Velocity and (b) dynamic pressure distributions of slotting nozzle in submerged condition
Authors mention uniaxial compressive strength but there is luck of discussion how it influences results.
Response: The uniaxial compressive strength will affect the slotting experiment result, but we test the uniaxial compressive strength to ensure the slotted material strength is close to the strength of the natural coal. Our aim is not to study the effect of uniaxial compressive strength on the results of slotting experiments
Author Response File: 
Author Response.pdf
Reviewer 2 Report
It is an interesting work of simulation and mathematical calculation.
It must correct:
References are cited in chronological order (lines 48,56, 60, 74, 78)
Line 70: indicate what SDHF is
Line 74: Nikonov reference?
The references are very local, they should internationalize.
Author Response
Reviewer 2:
References are cited in chronological order (lines 48,56, 60, 74, 78)
Response: We have sorted the references cited by time, according to the requirements of Applied Sciences, the format of references is adjusted.
Line 70: indicate what SDHF is
Response: SDHF is slotting–directional hydraulic fracturing. The slotting device does not rotate, but moves slowly and steadily in the vertical direction; the jets ejected from the slotting device and formed slotted holes in the coal seam. Finally, hydraulic fracturing is performed in the slotted hole.
Line 74: Nikonov reference? The references are very local, they should internationalize.
Response: We have replaced local reference with international reference, as follow.
Nikonov, G. P.; Kuzmich, I. A.; Garbuz, G. D. Hydraulic coal or ore mining optimal output determination-uses shield with slots for time based jets onto rock giving measurable breakout volume craters. 1978, Patent No. SU305266-A.
Author Response File: Author Response.pdf
Reviewer 3 Report
Dears Authors:
Your article titled "Structural Optimization of Slotting Nozzle Used to Improve Coal Seam Permeability" has been interesting to me. The problem of injection in the hydraulic fracturing of carbon has been one of the unsolved problems of the fracturing technique.
The use of finite element methods to model this problem is one of the most innovative research techniques.
Likewise, the evaluation of physical models has been satisfactory in the study of the problem.
The study of the background, methodology and discussion of results and conclusions seems to me correct and supported in their experiences of modeling and physics.
Congratulations
Author Response
Reviewer 3:
Your article titled "Structural Optimization of Slotting Nozzle Used to Improve Coal Seam Permeability" has been interesting to me. The problem of injection in the hydraulic fracturing of carbon has been one of the unsolved problems of the fracturing technique. The use of finite element methods to model this problem is one of the most innovative research techniques. Likewise, the evaluation of physical models has been satisfactory in the study of the problem. The study of the background, methodology and discussion of results and conclusions seems to me correct and supported in their experiences of modeling and physics. Congratulations.
Response: Dear reviewer, thank you for your approval of our article.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Is O.K.
