Dust Dispersion Characteristics of Open Stockpiles and the Scale of Dust Suppression Shed

Round 1

Reviewer 1 Report

 

Review report for authors

 

The aim of the paper proposition is to define the best scales of a shed to limit dust emissions and dispersion form a given stockyard including three stockpiles.

Introduction section:

The references cited are relevant but reflect not the huge bibliography dedicated, as examples, to the influence of stockpiles configurations or interaction, or to roughness influence.

End of third paragraph: PIV is not a “numerical calculation method” but an experimental method

Section 2.1:

“Fig. 1 shows the location and dimensions”: there isn’t any dimensions on Fig 1.

Fig Shows pictures of the real site. It appears that the pile’s shapes are not truncated cones as it’s supposed to define the numerical configuration.

For the numerical simulations, the height of the domain is 10m for piles with heights of 3.2m. This ratio seems very low and a sensitive study to this parameter would be necessary.

Very few information on the mesh is given. No figure presents the mesh, in particular the mesh structure close to the wall.

The inlet information for k and omega are not given: profils (and of paragaph 2.3.1, but no more information)

Section 2.3.1:

Eq 2.3 : no turbulence terms

“the roughness lengths on both the stockpile surface and the wall were fixed to be 0.03 mm”: how is this length taken into account?

Section 3.1: Validation

Numerical results are compared to experimental measurements. No information about the measurements is given: what kind of senors, what is the accuracy of the wind intensity and direction for the experimental runs?

The numerical results are analyzed for different wind velocities, but only for streamwise profiles, downstream the center pile and at a height of 1.5m.

It is very surprising that vertical and transverse profiles are not presented and analyzed. Interpretations based only on longitudinal (streamwise) profiles are undoubtedly very uncertain because the dispersion downstream of the heap is very strongly three-dimensional.

For the 12m/s velocity, the threshold value at 4mg/m3 is given for approximately 65m downstream the pile on Figure 7. On Figure 6, for 12m/s the 4mg/m3 threshold is closer to 80m.

This length is then used to define the characteristic length of the shed.

This approach is incomprehensible to me. In fact, the flow dynamics are radically different between, on one hand a free storage yard and, on the other hand a storage piles under shed. In the case of stockpiles under shed, the wind exposure is totally modified, so how can free atmopheric boundary layer flow results be used to estimate the shed size?

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The scientific quality of the article is good and the article contains the information needed to explain the essence of the problem and its solution.
The article is relevant to the journal Applied Sciences.

Reviewer comments:

Introduction. The introduction is sufficient.

The experimental specification section describes experimental methods. Sections describes the topic of article. Figures (in all article) have good resolution. Bud please provide fig. 4 - 9 in higher resolution or size.

The results and experiments are sufficiently explained in the Results section.

The summary and conclusion section correctly and sufficiently explain the measurement results. 

Notes:
1. In my opinion, the characteristics of the dust dispersion (sand), especially the size of the particles and their distribution, should be stated in the article.

2. The conclusion is quite short. Will research continue in this area?

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

 

Review report for authors on the revised version

 

Eq 2.3 : no turbulence terms. For turbulent flows RANS model, the momentum equations are the Reynolds equations included Reynolds tensor.

Eq 2.4 and 2.5: The Kolmogorov’s 1941 reference is probably not the right one.  Kolmogorov introduces omega for turbulent dissipation but the formulations of Eq 2.4 and 2.5 seem closer to, as example, Fluent documentaiton.

 

“==” in Eq 2.5

 

Section 3.2:

“On Fig. 5 compares the…” >>> “Fig. 5 compares the…”

 

Coverletter for the revised version:

Point 7: The inlet information for k and omega are not given: profils (and of paragaph 2.3.1, but no more information).

Response 7: In section 2.3.1, the k-omega turbulence condition has been added.

 

I don’t see the values or profiles for k and omega for the inlet condition in section 2.3.1

 

 

“Point 12: This approach is incomprehensible to me. In fact, the flow dynamics are radically different between, on one hand a free storage yard and, on the other hand a storage piles under shed. In the case of stockpiles under shed, the wind exposure is totally modified, so how can free atmopheric boundary layer flow results be used to estimate the shed size?”

 

I maintain this remark with regard to the sizing method.

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf