Hello, everyone.
I am honored to participate in the discussions on the forum. Currently, I am researching the blade icing and its adverse effects on floating wind turbines operating in cold regions. After a period of self-study, I have gained a general understanding of the working principle of OpenFast. But due to my limited knowledge, there are still some issues with running OpenFast. These questions do not involve specific techniques, only requesting some inspiration.
As mentioned earlier, I calculated the ice accumulation of airfoils with different blade lengths under various icing conditions, and obtained the icing mass of the airfoil and the new lift and drag coefficients of the airfoil. I was inspired by the relevant discussions on airfoilprep regarding the correction of lift coefficient and other factors. But what I still don’t know is, where should I make corrections to the blade mass to calculate the impact of additional ice mass on the wind turbine structure (blades)? Additionally, what numerical values (such as torque) can I obtain through OpenFast to assist in analyzing significant ice breaking? Perhaps there have been similar discussions on the forum, but unfortunately, I am still a pure novice in the field of structure. Dear experts, please let me know the relevant discussion titles.
In addition, regarding the hydrodynamic part, in my rough opinion, the slight ice buildup on the blades should not be enough to affect the overall movement of the wind turbine, at least relative to wind and waves. Can we directly use the hydrodyn file from the OpenFast case (r-test)?
Please forgive my poor English.
Dear @Huan.Xia,
The mass of the ice for an iced blade can be added directly to the structural mass, which is specified per unit length in either the ElastoDyn blade input file (if you are modeling the blades in ElastoDyn) or in the BeamDyn blade input file (if you are modeling the blades in BeamDyn). Either way, you can specify the mass locally long the blade, as well as independently between blades, if needed.
I’m not sure I understand your HydroDyn question.
Best regards,
Dear @Jason.Jonkman
Thank you so much for your detailed explanation, which has been immensely helpful for my study and research.
Regarding the hydrodynamic calculation section, my prior confusion lies in whether certain parameters in the HydroDyn input file need to be modified. Specifically, I would like to confirm whether it is feasible to keep the input file fully consistent with that used for the smooth (ice-free) blade condition in the calculation. The root of this confusion is that I am uncertain whether the impacts of blade icing (i.e., the additional mass and aerodynamic performance degradation) on hydrodynamic calculations will necessitate adjustments to some parameters in the HydroDyn input file.
Once again, I greatly appreciate your response. I have long been engaged in fluid mechanics research, and have very limited knowledge of structural dynamics and hydrodynamics. For this reason, every single response from you has been of tremendous help to me.
Dear @Huan.Xia,
In a floating wind turbine application, the HydroDyn module is applied to the hydrodynamic loading of the floating substructure, but it does not directly impact aerodynamic loading of the blades, which is handled by AeroDyn.
Of course, if there is ice loading on the blades, there could just as well be sea ice loading of the floating substructure, but this is handled separately in OpenFAST through the CompIce features.
Best regards,