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Table of Contents

Ailerons

The user can include the influence of ailerons in a Bladed simulation. An aileron is a section of blade that is typically outboard of the blade that can be pitched. An aileron is denoted as being a succession of Moving sections between one or more “Fixed” sections. It is not possible to have two adjacent ailerons.

To use the Aileron functionality a user must:

  • Define suitable Aerofoil Datasets to describe the affect of ailerons when they pitch.
  • Define Aileron sections as part of the Blade inputs.
  • Define the Pitch Response of the Aileron in Project Info.
  • Use the Controller to specify changes in Aileron Deployment Angle.

Defining Aileron Sections

An aileron section should be defined for every blade station which is defined as Moving (see MissingReference Blade geometry). Assuming Ailerons are specified for the aerodynamic control surfaces. Flaps and air brakes can be treated as if they are ailerons.

For any parts of the blade which have flaps, ailerons, air brakes or other aerodynamic control surfaces which alter the aerodynamic profile of the blade section. Separate aerofoil datasets may be provided for a number of different deployment angles of the control surface. Interpolation between these datasets will be used to give aerodynamic coefficients appropriate based on the deployment angle at any point in the calculation. Linear interpolation is applied and nearest neighbour values are used if the range of deployment angles and angles of attack are exceeded.

Aileron sections allow interpolation between a set of Aerofoil Datasets defined for different aileron deployment angles.

A number of different aileron sections may be defined if required, for use at different blade stations.

Editing Aileron Sections

On the Blade properties window, click on the foil section to be defined. A drop-down list allows an already-defined section to be selected, or select Define\... to open the Define Aerofoil Sections window. This allows the characteristics of already-defined sections to be viewed or edited, or new ones created by clicking New.

To view or edit an existing aerofoil section navigate to the Define Aerofoil Sections window and select the section number required.

To set up a new aerofoil section navigate to Define Aerofoil Sections window and press New to start a new foil section.

To edit an Aerofoil section click Add or Insert to increase the number of Aerofoil Datasets to interpolate between. Click Delete to remove one. Double-click on any entry to open the Aerofoil Dataset Selection window. This presents a list of all suitable datasets from the database (they must be in ascending order of deployment angle). If desired, the selection criteria may be modified to further restrict the list displayed. Select a dataset from the list and click OK.

No entries may be left blank.

To remove an aerofoil section:

There is no need to delete an aerofoil section if it is no longer needed at any blade station. The sections which are still in use will be renumbered when the Blade Properties window is closed, starting from 1. The aerofoil datasets themselves of course remain in the database.

Aileron Pitch System

Project Info can be used to provide additional information about the ailerons. This defines the response to pitch angle demands from the Controller.

MSTART EXTRA
PitchAndAileron 1 * 1 means whole blade pitches according to pitch
demand, and ailerons move additionally according to aileron angle demand
Angle 0 *Initial or steady state aileron angle (rad) (default = 0)
AileronActuator 1 *Default 0 for instantaneous response, *Only if AileronActuator=1, we then need the transfer function for the
aileron response:
*Example for first-order response, time constant 0.1s:
Aileron_NUMORD 0 * order of transfer function numerator
Aileron_NUM 1 * numerator values of transfer function
Aileron_DENORD 1 * order of transfer function denominator
Aileron_DEN 0.01 1 * denominator values of transfer function
MEND

Controller Functions to Change Aileron Deployment Angle

The rotor dynamics can be controlled by changing the aileron deployment angle. The calculation will then interpolate between the aerofoil datasets within an Aileron section. A user can make use of "SetDemandedAileronAngle" or "SetDemandedAileronAngleOnHubN" in the Controller API. The equivalent accessors in the Swap Array Controller can be identified.

Last updated 15-11-2024