Coupled CFD-DEM Simulation of Seed Flow in Horizontal-Vertical Tube Transition
Round 1
Reviewer 1 Report
This manuscript is of scientific and practical interest. It presents the results of a series of simulations of the movement of loose particles, in this case peas, in the pneumatic channel of the seeder. Simulations are performed for different air flow velocities, different bending radii of the pneumatic tube. Also, when modeling, a comparative analysis of two modeling methods was carried out, taking into account the influence of air flow: one-way communication and two-way communication.
The article is presented clearly with enough data to understand the problem being solved. A fairly complete review of scientific papers on this topic has been conducted. There is a sufficient amount of digital information in the work that allows us to evaluate it as a completed scientific work.
However, the paper lacks the results of comparative studies of at least one of the variations of the real process under study using a laboratory setup that would allow assessing the adequacy of the simulation. Also, the simulation results can be significantly influenced by such factors as: the humidity of the initial bulk medium, the presence of a seed shell (coating after pre-sowing treatment), the variational distribution of seed sizes by size (small and large seeds will have different trajectories), the initial parameters of seed input, the time step of calculation, the size of the grid and others. Also in the article it was desirable to provide comparative information on the calculation time using various methods. How much they differ in the complexity of calculations.
The figures given in the article are easy to read and have sufficient completeness of information.
The conclusions obtained reflect the results of the conducted research, resulting from them and justified in the course of the work carried out, which is a significant advantage of this work.
This work is theoretical in nature and can later be used by other scientists as a basis and supplemented with the results of laboratory studies or a comparative analysis of modeling the same process in other discrete-element modeling systems.
Author Response
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Reviewer 2 Report
Comments for author File: Comments.docx
Author Response
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Reviewer 3 Report
1. The abbreviation “CFD-DEM” should also be explained in the abstract.
2. In the Key words, it is necessary to write “Computational Fluid Dynamics”, “Discrete element method” in full form, not “CFD”, “DEM”.
3. In the Line 38: “Computer simulation methods are useful in representing...” part, it would be good to cite the manual or book where computer simulation methods are given, i.e. Computer simulation methods [7] are useful in representing... .
4. The some work applies to “Computational Fluid Dynamics (CFD) and the application” in line 44 and “discrete element method (DEM)” in line 47-48, that is “Computational Fluid Dynamics (CFD) and the application […]” and “discrete element method (DEM) […]”.
5. In Table 1: Why Particle Density Pea Seed – 1720 кг/м3 was accepted. Isn’t Bulk density possible in interval Pea Seed 600 – 800 кг/м3 ?
6. Is the critical velocity of Pea seed 15 – 17 m/s taken into account in the used model and calculations?
7. In Table 3, Set 3, Elbow diameter was given 48.3 x 10-3 / 60.3 x 10-3 / 72.4 x 10-3 m in Parameter column. I think in this case it should be 72.3 x 10-3 instead of 72.4 x 10-3 m.
8. In the Coupled CFD-DEM Simulation of Seed Flow in Horizontal-Vertical Tube Transition, what assumptions were accepted, was the turbulence condition taken into account?.
Author Response
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Reviewer 4 Report
The authors presented Coupled CFD-DEM Simulation of Seed Flow in Horizontal Vertical Tube Transition. The paper is well prepared with very good scientific soundness. It can be accepted after minor revisions:
The novelty of the work is to be clearly stated at the end of the introduction.
A figure presenting the mesh used in the CFD study is to be added.
The numerical method is to be described with more details.
What is the convergence criterion?
A grid sensitivity test is to be performed.
A qualitative (flow structure for example) validation/verification is to be performed by comparing with earlier published results.
The authors considered 3D geometry, thus some 3D results are to be presented (flow structure for example)
Fig 4 has very low resolution.
What is the range of Reynolds number corresponding to the considered velocities.
What is the interest of the presented dimensional analysis?
The paper is to be checked against misprints and grammatical mistakes.
Author Response
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