The manuscript investigates if a forced motion approach is a good complementary analysis tool to fully-coupled analyses for the study of wind turbine blade VIVs. The study compares both approaches for a 10MW wind turbine blade, with a focus on the impact of the structural damping and the initial conditions. The manuscript is well written and of high relevance to the field.

I have the following questions/clarifications on some of the results.

- Fig 6. The figure shows the power injected by the motion for different motion amplitudes. The authors point at large power injections beyond amplitudes of 1m. However, in certain cases, large power injections are also apparent at smaller amplitudes (with power injection values larger than close to the max amplitude of 1.6m). Isn’t the positive value of power more important than the amplitude value? (i.e. large P at A=0.6m could be more problematic than smaller P at A=1.6m). This could be clarified in the text.

- Fig 9. There is an overall good agreement between FM and FSI values of Pcycle over the blade radius. Can the authors comment (also based on previous studies) on how much local positive values of Pcycle can trigger VIV by propagating throughout the whole blade? Following this, could some of the differences observed between FSI and FM be an issue for predicting VIV occurrence based on FM simulations?

- Based on the results of this paper, it would be interesting to investigate a wider parameter space for VIV under forced motion. Is that planned as future work?

Publisher’s note: the supplement to this comment was edited on 9 September 2022. The adjustments were minor without effect on the scientific meaning.

In the paper, the authors attempt to correlate the predictions of advanced CFD, imposed motion simulations with those of fully coupled CFD aeroelastic analyses. One of the aims of this work is to allow prediction of the limit cycle amplitudes of a rotor blade in lock-in conditions, based on forced motion analyses, instead of (if possible) the computationally expensive fully coupled FSI analyses.

The paper is well prepared and the work is extremely relevant for the wind energy community.

I don’t have much to say about the paper. I read it with great interest and I found the conclusions important and the whole work worth publishing.

My only concern is that full wind turbine aeroelastic analyses indicate that the coupling of the rotor with the rest of the turbine (tower etc.) significantly alters the coupled out-of-plane modes (in terms of frequency and damping) of the full system compared to the isolated blade modes. However, the authors acknowledge the above mentioned point in their conclusions section and they add that the only limitation for performing a full rotor analysis is computational cost which sounds reasonable.

Given the above I recommend publication of the paper with minor revision. Some corrections/comments have been added in the accompanying pdf.