Multi Rotor Turbine Assembly

QBlade-EE

This feature is only available in the Enterprise Edition of QBlade.

Visualization of a Multi-Rotor Turbine Assembly.

Fig. 114 Visualization of a Multi-Rotor Turbine Assembly.

A turbine with multiple rotors may be defined in the dialog Menu->Turbine Definition->Create a Multi-Rotor Turbine Assembly. A Multi-Rotor Assembly requires the definition of a common substructure, see Substructure Modelling. The common substructure definition must then contain multiple transition pieces (TP_INTERFACE_POS) that may have different orientations (TP_ORIENTATION). If a common substructure is loaded into the Multi Turbine Assembly dialog (see Fig. 115) a turbine from QBlades database (that contains its own structural definition and controller) can be assigned to each of these transition pieces. Multiple transition pieces can be defined by adding _2, _3, _4, …, _N to the respective keywords, such as TP_INTERFACE_POS_2 and TP_ORIENTATION_2, where the appendix _1 can optionally be omitted for the first transition piece and all associated keywords. For any additional transition piece TP_INTERFACE_POS_X, the following keywords may be defined:

  • REF_COG_POS_X

  • REF_HYDRO_POS_X

  • TP_ORIENTATION_X

  • SUB_MASS_X

  • SUB_HYDROADDEDMASS_X

  • SUB_HYDROSTIFFNESS_X

  • SUB_HYDRODAMPING_X

  • SUB_HYDROQUADDAMPING_X

  • SUB_HYDROCONSTFORCE_X

  • POT_RAD_FILE_X

  • POT_EXC_FILE_X

  • POT_SUM_FILE_X

  • POT_DIFF_FILE_X

  • AZIOFFSET_X

  • ROTFACT_X

To connect to a specific transition piece in the SUBCONSTRAINTS table simply use the number X of that transition piece in the TrPID column.

The Multi-Rotor Assembly Dialog.

Fig. 115 The Multi-Rotor Assembly Dialog.

Multi Rotor Turbine Assembly Keywords

Two keywords can be used to specify the initial rotor position in a multi-rotor turbine assembly and the relative rotational speed of a rotor in relation to the rotational speed of the master rotor. These keywords have to be defined in the common substructure file.

AZIOFFSET_X

Offsets the initial azimuthal angle of the rotor by this angle (in °).

Listing 28 : AZIOFFSET
120     AZIOFFSET_2
PITCHOFFSET_X

Offsets the initial collective pitch angle of the rotor by this angle (in °).

Listing 29 : PITCHOFFSET
2       PITCHOFFSET_2
YAWOFFSET_X

Offsets the initial yaw angle of the rotor by this angle (in °).

Listing 30 : YAWOFFSET
15      YAWOFFSET_2
ROTFACT_X

Sets the rotational rate of a slave’ rotor in relation to that of the *master rotor. This value is only in effect if the simulation is performed with a fixed rotational rate (see Rotational Speed Settings). If the simulation is carried out with a free rotational rate this value has no effect.

Listing 31 : ROTFACT
0.9     ROTFACT_2

Multi Rotor Turbine Assembly ASCII File

A Multi Turbine Assembly can be exported or imported in the .mta format. The file content points towards the common substructure file and towards the turbine (.trb) files that are used in the multi-rotor assembly. See an exemplary .mta file below:

----------------------------------------QBlade Multi Turbine Assembly Definition File-------------------------------
Generated with : QBlade IH v2.0.2_alpha windows
Archive Format: 310003
Time : 18:25:50
Date : 04.07.2022

----------------------------------------Object Name-----------------------------------------------------------------
double_OC4                               OBJECTNAME         - the name of the multi-rotor turbine object

----------------------------------------Assembly Definition---------------------------------------------------------
OC4_DeepCWindSemi_Sub_LPMD.dat           SUBSTRUCTURE       - the path of the common substructure file that is used in this multi turbine assembly
NREL_5MW_OC4.trb                         MASTER             - the master turbine of the assembly
NREL_5MW_OC4.trb                         SLAVE_1            - the slave turbine(s) of the assembly