Extracting Wake Data with Cut-Planes

When a simulation of a Wind Turbine Design with a Free Vortex Wake has been performed it is possible to extract velocity distributions from the simulation.

Wake velocity distribution generated from a LLFVW simulation.

Fig. 105 Wake velocity distribution generated from a LLFVW simulation.

Velocities can either be calculated and visualized using a Cut Plane Definition or by exporting velocity data in a 3-dimensional field. The dialog to generate cut-planes or to export velocity fields is found in the Dock Window of the Turbine Simulation module in QBlade. If the dialog does not appear in the dock window it can be shown by selecting the option Show Cut Plane Options in Dock in the top menu (see Fig. 106).

The cut-plane option in the *Dock Options* menu of the *Simulation Module*.

Fig. 106 The cut-plane option in the Dock Options menu of the Simulation Module.

In the cut-plane dialog (see Fig. 107) one or multiple cut planes can be generated by defining the plane center, its dimensions and orientation. If the replay (see General Simulation Settings) of a simulation has been stored it is also possible to automatically generate cut planes for each timestep of a simulation by choosing the + all next option. The % x box allows to selectively only generate cut-planes when mod(timestep,x) = 0. If the box average is ticked an average velocity field (averaged over all timesteps) is created for each cut plane definition. The checkbox rotor fixed allows to automatically rotate a cut plane definition with the current rotor position.

The cut-plane options dialog.

Fig. 107 The cut-plane options dialog.

It is also possible to export a cut-plane definition (see Fig. 108) to facilitate the cut-plane generation in batch processing when using the Command Line Interface (CLI) or to generate a cut-plane for multiple simulations from the same definition.

The cut-plane export option.

Fig. 108 The cut-plane export option.

An exemplary cut-plane definition file is shown below.

Listing 85 : An exemplary cut-plane definition file
---------------------------------QBlade Cut Plane Definition File-------------------------------------
Generated with : QBlade EE v2.0.6.1_beta windows
Archive Format: 310012
Time : 17:14:48
Date : 31.05.2023

112.097                                 XPOS
0.000                                   YPOS
150.195                                 ZPOS

0.000                                   XROT
90.000                                  YROT
0.000                                   ZROT

302.425                                 LENGTH
302.425                                 WIDTH

200                                     XRES
200                                     YRES

false                                   ALL
false                                   AVERAGE
1                                       MODULUS
400                                     TIMESTEP