Plane analysis

Unlimited number of wings

The plane configurations can now include any number of wings.

For increased versatility, each wing and fuselage part can be rotated around the x- and y-axis.

Fuselage

Planes with fuselage

Unlike in xflr5, the analysis of planes with fuselage is implemented adequately in flow5.
The two issues with xflr5 are that
(1) the wings can only be modelled as thin VLM surfaces, and the potential influence of VLM panels on fuselage Dirichlet panels cannot be calculated
(2) there are no built-in tools to mesh the connection of the wings to the fuselage

In flow5, thin surfaces can be modelled as source/doublet panels and not only vortex panels, and the use of OCCT libraries has enabled the meshing of wing and body connections.

External fuselage design

3d fuselage designs from external C.A.D. software can be imported into flow5 using the STEP, IGES and STL formats. The conversion of STEP and IGES files is performed by the OCCT library, and preliminary testing has shown that this is done without loss. The recommended format is STEP.

Once imported, these fuselage types are handled internally as B-Rep objects. Their intersections with the wings are performed by functions available in the OCCT library. The triangular surface mesh is constructed by a custom mesher.

STL designs can be imported and will be converted as-is into triangular surface meshes ready for the Galerkin analysis. These STL models can only be modified within flow5 by scaling, translation and rotation operations.

Due to the difficulty of achieving smooth surface triangular surface meshes, some pre-processing in the C.A.D. software is recommended before exporting the model to flow5 in order to obtain reasonable results. See this video (link) for more information.

Multiple fuselages

The program can handle multiple fuselages, however it only manages the intersection of the wings with the central fuselage. Configurations such as the P38-lightning or the Stratolaunch are not handled.

Fuselage drag models

The Karman-Schoenherr and Prandtl-Schlichting drag models have been implemented to account for fuselage drag. Other models may be added in the future based on user requests.