Please see attached file.

 An insight into the capability of the Actuator Line Method to resolve tip vortices - wes-2023-88

General comments

Not being familiar with the ALM subject I thought I a very difficult review. I am happy to report that despite the novelty of the subject (for me), the paper allowed me to understand a great deal of the overall subject and the authors interest.

Overall, the paper is well written with useful plots illustrating the points the authors wanted to make. Despite some minor syntax errors mostly attributed to the paper’s length the text can be read easily.

Being unexperienced in the topic, having sections dedicated to the state of the art and explanations about the theory was very useful, although it may be redundant for more experienced readers. Having such sections in appendices could have been another option.

The comments and questions below are for my clarification.

I believe that the paper should be accepted after the minor comments  in the questions below are answered.

Technical comments

1. I understand the need of a well known and simple aerofoil such as NACA 0018, despite no longer being used in wind turbine designs. However, the Reynolds number is too low to be representative of modern wind turbine, some viscous effect may still be seen thereby possibly questioning the outcome. Such study would have been preferential above Re = 2-3 10^6. Did you choose 500k in order to save some computing time ?
2. The turbulent intensity seems quite high compared to wind tunnel experiment or even some wind farm sites following the IEC classification. Why did you choose 1 % and not a lower value (which could have helped your CFD simulation) ?
3. The CFD setup followed a previous work performed by the authors, the RANS approach tends to smooth out any flow unsteadiness and presents only averaged results. When looking at the unsteady phenomena of tip vortices, another approach would have been more pertinent such as LES or (i)DDES even URANS. Did you perform sensitivity studies on the CFD baseline as it could impact the rest of the study (such as the AoA recognition) ?
4. Similarly, the vortex detection may not be fully accurate using a RANS approach rather than a time varying one.
5. Very impressive 2D CFD results matching the experimental CL and CD !
6. Did you average the whole wing to produce the CL and CD curve for the 3D BR-CFD (fig 4) ? It could have been interesting to plot some of the different positions along the span as used further down the paper to illustrate the spread in results
7. Figure 7 and Figure 8 are very clear highlighting the three-dimensionality effect introduced by the finite wing. Because of the RANS solver 3D cases may not be truly those plotted, or at least the error bar due to the unsteady nature cannot be seen.
8. To complete those interesting figures (Figure 7 and Figure 8), it may be useful to add onto the wing shape the 3D AoA contour (if feasible) ? It could show interesting pattern regarding its spanwise evolution.
9. The evolution of the radial flow component could also be plotted onto the wing surface since its behaviour is monitored in the next sections.
10. Did the 3D AoA calculations account for the radial flow in the Cp calculation? The equation 9 mention the local velocity, is the possible “flow deviation” due to the tip accounted for ?
11. The sentence in Line 389-394 (However, the magnitude…) is very important and should be split into several sentences to avoid losing the reader.
12. The conclusion is clear and well written summarizing the outcome and future work. Will the bullet point 2 solve/address the issue in bullet point 3 ?