How does AeroDyn compute the aerodynamic loads

Wind & Water Rotor Aerodynamics
1

Hello,

In the documentation about Aerodyn module, it is mentioned that:

AeroDyn calculates aerodynamic loads on both the blades and tower. Aerodynamic calculations within AeroDyn are based on the principles of actuator lines,

This is confusing, because the actuator line method by design can work only with a computational domain (requires a CFD solver). As an example, I quote this (from this PhD thesis):

The actuator line method, introduced by Sørensen and Shen [75], is a fully three-dimensional
and unsteady aerodynamic model for studying the flow field around wind turbines. The method combines a three-dimensional Navier-Stokes solver with a so-called actuator line technique in which body forces are distributed radially along lines representing the blades of the wind turbine.

Could you please clarify the confusion? I assume that documentation is referring to “Actuator disc” concept (for example, as explained here) not “Actuator line”?

In addition, the current documentation seems to contradict the old Theory manual (link: https://www.nrel.gov/docs/fy05osti/36881.pdf). The Theory manual explicitly explains the Actuator disk concept (starting from page 13 of the PDF file).

Best regards,

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Update: I am now more inclined to believe the confusion arises because the AeroDyn documentation uses the term “Actuator line” to refer to “Lifting line method” (which are two distinct methods). This distinction can be quite misleading, and if that is the intended meaning, it would be important to clarify it in the documentation to avoid further misunderstanding.

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Dear @Yoor.Thiziri,

It looks like you asked a similar question in the following forum topic, which I had answered previously: Which method is used in OpenFAST? BEM or Actuator Line method?.

Best regards,

1 Like
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Dear @Jason.Jonkman
Many thanks for your reply. I apolgize for opening this post here again. I will continue the discussion on the other linked post instead.

Best regards.